Black Granite Varieties: A Buyer's Guide to Names, Origins and What Actually Differs

If you import black stone, you already know the problem. Two quotations arrive, both say "black granite", the prices differ by thirty percent, and nothing on either sheet tells you whether you are comparing the same material or two rocks that only share a colour.

This guide is written for importers, fabricators, monument wholesalers and project procurement teams buying in container volumes. It works through what the common black granite names actually refer to, what is documented about their geology and physical properties, where the naming breaks down, and how to compare two black materials on properties you can specify and test rather than on a trade name. The two Chinese materials — Shanxi Black and G684 Fuding Black — are covered in the most detail, because they are the ones most buyers sourcing from China will be offered first.

One thing up front, because it shapes everything below: a black granite name is a commercial label, and a commercial label is not a specification. It tells you what the market calls the stone. It does not tell you what the stone is, where it came from, or whether the container you receive will match the sample you approved.

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Black Granite Types: Why the Names Tell You Very Little

There are two separate naming failures in this market, and buyers run into both.

The first is one stone under many names. Shanxi Black is a documented example. The same material is traded as Shanxi Black, as 太白青 (Taibaiqing), as 帝王黑, and in English-language markets as Dynasty Black. Four names, one deposit in Hunyuan, Shanxi Province. A purchaser who receives quotations for "Dynasty Black" and "Shanxi Black" from two suppliers may be looking at the same blocks priced twice — or at two different suppliers using the same marketing name for material from different pits. The name does not resolve the question.

Black Galaxy shows the same pattern. The material quarried near Chimakurthi in Andhra Pradesh also moves as Star Galaxy, Galaxy granite and Ongole Galaxy. Some of those names travel with the stone; some are applied by individual exporters. Because "Galaxy" is used loosely, a quotation carrying the word does not tell you which quarry the slabs came from.

The second failure is many stones under one name. This is the more expensive one. "Absolute Black" is now a category name, not a single-origin product. Material sold under it is produced in India, South Africa, Zimbabwe and China, and quality varies by quarry. A buyer who specifies "Absolute Black" believing it describes one deposit in one country is specifying an appearance, not a source.

The practical consequence is simple and worth stating plainly: a name in a quotation is not an acceptance criterion. If the purchase order contains nothing but a trade name, there is nothing to inspect against and nothing to claim against if the container disappoints. The rest of this guide is about what to put in place of the name.

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What "Black Granite" Actually Means in the Trade

Start with geology, because it explains why the name behaves the way it does.

True granite is composed of quartz, light-coloured feldspar and mica, and it is typically light in colour. That is the mineralogical definition, and most stone sold as black granite does not meet it.

What is actually sold as black granite is, in most cases, a dark mafic igneous rock — dolerite (also called diabase), basalt, or gabbro. These are different rocks with different mineralogy, different hardness and different working behaviour [source: stonecrestinternational.com].

So why does the trade keep using the term? Because it is permitted to. ASTM C119 allows these dark igneous rocks to be quarried and sold under the name "black granite" [source: stonecrestinternational.com]. The term is a trade classification with a standard behind it, not a mineralogical claim.

This is the point where buyers go wrong in both directions. It is not accurate to say black granite is granite. It is equally not accurate to call it fake granite or a mislabelled product. The correct statement is narrower and more useful: commercial naming and geological naming are two different systems, and ASTM C119 explicitly allows them to diverge. A stone can be correctly sold as black granite and correctly classified as a basalt at the same time. Both labels are doing their own job.

That distinction has a direct commercial consequence. If you buy on the word "granite", you may be treating a basalt and a dolerite as interchangeable. They are not. G684 Fuding Black is a basalt, and its reported hardness sits below that of the hard granite-type blacks — a difference that shows up in tooling cost, edge work and abrasion performance. Two "black granites" can occupy different positions on the hardness scale, and the shared word hides it.

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Where the Black Colour Comes From

Understanding the colour source helps a buyer read a sample, because "how black" turns out not to be one property.

Three mineral causes produce the dark tone:

1. Calcium-rich plagioclase feldspar — the labradorite–bytownite range. These are considerably darker than the sodium-potassium feldspars found in true granite, which is why a rock can be feldspar-rich and still read as black.
2. Pyroxene — augite and pigeonite. These minerals are near-black in hand specimen.
3. Iron oxides — magnetite, titanomagnetite and ilmenite — occupying the spaces between crystals.

Most black dimension stone combines all three in varying proportions, and the proportions are what a buyer is really looking at. A material where fine pyroxene and iron oxides dominate, with crystals too small to resolve individually, polishes to a uniform field. A material with larger plagioclase crystals shows grain, and the grain becomes a specification item in its own right — which is exactly what happened with Shanxi Black, discussed below.

For a buyer, this translates into three questions to ask of any sample, rather than one:

• Base colour — how dark is the field?
• Grain size — are individual crystals visible, and at what scale?
• Uniformity — does the appearance hold across the slab, or change across the block?

Photographs answer none of these reliably. The same slab photographed wet and dry reads differently, and factory lighting flatters a polish.

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Chinese Black Granite: The Two Names That Matter

For buyers sourcing from China, two names dominate the black stone conversation in export volumes: Shanxi Black from the north and G684 Fuding Black from the Fujian coast. They are frequently offered against each other, and they are not equivalent materials.

Shanxi Black (山西黑)

Shanxi Black is quarried at Hunyuan, in Shanxi Province, and geologically it is a gabbro-diabase (辉绿辉长岩) — a dark intrusive rock, not a true granite in the mineralogical sense.

The composition explains the material's position in the market. Plagioclase at roughly half the rock, augite–pigeonite at roughly a third, with iron oxides filling the interstices — that is the mineral recipe for a dense, hard, near-opaque black, and the reported figures bear it out. A Mohs hardness of around 7 and a density of 2.9–3.2 g/cm³ place it at the upper end of the values discussed in this guide. Fine-grained and massive in texture, it takes a high polish and holds a crisp edge, which is why A-grade material is commonly directed to monument work.

The grain classification deserves a buyer's attention because it is a within-material distinction, not a different stone. Shanxi Black is sorted into 大花 (large grain), 中花 (medium grain) and 细花 (fine grain) according to crystal size, and the mid and fine grain material is generally the more sought after. If your project calls for a large area of uniform black, the grain grade affects how the finished surface reads, and it should be written into the order rather than left to the supplier's discretion.

The deposit figures are worth reading for what they say about supply. A reserve of 193 million m³ with block output of approximately 35,000 m³ per year describes a deep deposit with a production rate that is modest relative to the reserve — a supply picture that matters when you are planning repeat orders across a multi-phase project. Note that these are quarry-level figures. They describe the deposit, not your shipment; they are not a substitute for batch documentation.

Finally, the four trade names on one material is the single clearest illustration of the naming problem in this guide. If you are comparing quotations for Shanxi Black, 太白青, 帝王黑 and Dynasty Black, ask each supplier for the quarry location before you assume you are comparing like with like.

G684 Fuding Black (福鼎黑)

G684 is the Fujian export code, and the material behind it is basalt — not a granite. This site archives it accordingly: G684 Fuding Black.

The rock type is the headline. G684 is sold into the same black stone market as the granite-type blacks, competes on the same quotations, and is classified by ASTM's commercial convention under the same "black granite" umbrella — while being a basalt. This is the example to keep in mind whenever a quotation says "black granite" and nothing else. The site's own product page for G684 files it as basalt, and that classification is the geologically accurate one.

Hardness is where the difference becomes commercial. The reported hardness for G684 is lower than that of Shanxi Black and other hard granite-type blacks such as Fengzhen Black. No single figure is quoted here, and a buyer should not assume one — the honest position is that the material sits below the hard granite blacks on the scale, which makes it a different proposition for abrasion-heavy work. For general interior and exterior decoration, architectural components, countertops, wash basins and monument stock — the documented applications — that hardness is sufficient and the material performs. For work where the stone must resist heavy abrasion or accept fine carving and crisp repeated edge profiles, the harder material is generally the safer specification. A fabricator pricing tooling and polishing time should know which side of that line the material sits on before quoting the job. Verify on a physical sample rather than on the code.

Bulk density is quoted as 2.86. Note the basis: the figure is given as a bulk density, whereas the density figures elsewhere in this guide are quoted in g/cm³. This is a real buyer trap. Density figures published by different sources are not measured or expressed on the same basis, and comparing a bulk density against an apparent or true density is not a like-for-like comparison. Ask what basis the number is on before you use it for anything.

Alkali resistance of 99.93–99.96% is a reported performance figure. For a material specified in wet or alkaline environments, that is a favourable number, but the reported figure should be tied to a test basis if it is going to carry weight in a specification.

The industry history is unusual and worth knowing. G684 once accounted for 80% of China's black stone market, and at its peak the district ran 348 workshops. In 2018, environmental integration consolidated that into 28 joint-stock companies plus 2 deep-processing enterprises. For a buyer, that is a structural change in who you are dealing with: material that was once cut by hundreds of small yards now comes from a much smaller number of larger producers. Supply may be more consistent, and supplier identity more stable, than it was — but you should verify who you are actually contracting with, since the trading names in the market may predate the consolidation.

Other Chinese Blacks

Beyond the two main names, several other Chinese blacks circulate in export quotations:

• 蒙古黑 and 丰镇黑 (Mongolian Black and Fengzhen Black) from Inner Mongolia — documented as hard granite-type materials. Fengzhen Black is the reference point against which G684's hardness is reported to be lower.
• 河北黑 (Hebei Black), also sold under the name 中国黑 (China Black) — a Hebei-origin black moving under a generic national label.

The generic label is worth pausing on. "China Black" is a national name applied to material from a specific province, and it is the kind of name that tells a buyer close to nothing about origin. Where a supplier offers "China Black", treat it as a category description and ask for the province, the quarry and a sample.

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Indian Black Granite: Absolute Black Granite and Black Galaxy Granite

India is the other major origin offered to importers sourcing black stone, and the two names that dominate are Absolute Black and Black Galaxy. Both carry naming and property traps that are specific to them.

Absolute Black

The geology explains the appearance. Absolute Black is a dolerite — an ancient intrusive that pre-dates the Deccan volcanic activity — quarried across several districts of Karnataka within the Dharwar Craton. Its texture is fine to medium grained and ophitic, which means the crystal interfaces are small and intergrown to the point that no visible crystal boundaries remain after polishing. That is the mechanism behind the material's characteristic uniform, mirror-like black field. It is not a marketing description; it is a consequence of the rock's texture, and it is the reason Absolute Black behaves differently from a grained black under close inspection.

For a buyer whose requirement is a genuinely uniform black field — a large reception desk, a matched wall elevation, a memorial — the texture is the property that delivers it, and it should be checked on a sample of the actual slab rather than inferred from the name.

The physical figures put Absolute Black within the granite band on hardness: 6–7 on the Mohs scale, with a density of approximately 2,800–3,000 kg/m³. The water absorption range of approximately 0.05–0.30% is deliberately quoted as a range, because sources report different values. That width is itself information. A range spanning six-fold is not a specification; it is a signal that the number varies by quarry, by block and by test. If absorption matters for your application, specify the value you will accept and have the delivered batch tested, rather than exchanging industry ranges with your supplier.

And the naming caution stands as the most important line in the table above: "Absolute Black" is a category name. India, South Africa, Zimbabwe and China all produce material sold under it. Quality varies by quarry. A quotation offering "Absolute Black" without a quarry or district reference has not told you what you are buying.

Black Galaxy

The hardness figure is the single most important line on this page for a buyer. Black Galaxy reports a Mohs hardness of approximately 4.5, which is clearly below the 6–7 that granite typically occupies. The practical meaning is direct: the material is more easily scratched than the other blacks discussed here. That does not make it unsuitable — it is a widely traded and visually distinctive stone — but it changes where it should go and how it should be handled. High-traffic flooring, heavy-use work surfaces and applications where abrasive contact is routine are different propositions at 4.5 than at 7. The specification conversation should happen before the order, not after the first complaint.

The gold flecks are iron-rich enstatite, also called bronzite. That is the material's defining feature and the reason it is specified at all. Note that the flecks are a mineral inclusion, not a defect and not a finish — a supplier cannot add them or remove them, and their density and distribution are inherent to the block. If a project depends on a particular fleck density, that has to be assessed on samples from the actual production lot.

The geology is worth stating precisely: Black Galaxy is a gabbric anorthosite, and it is not a true granite. As with Absolute Black and G684, the trade name and the rock name are separate systems.

Slab yield is the commercial fact that catches importers out. Only 30–40% of production reaches large gang-saw size — defined as slabs above 2.40 m × 1.20 m × 1.00 m. Put in buying terms: the majority of production does not reach large-format slab dimensions. If your project needs matched large slabs, you are competing for a minority share of output, and both the price and the lead time should be planned around that rather than assumed. The quarrying is spread across roughly 40 quarry sites over 400+ acres, with export moving through Chennai and Krishnapatnam.

Prices and tonnage figures circulate widely for Black Galaxy. Where published sources conflict, the honest position for a buyer is to rely on the specific, measurable facts — hardness, yield at large format, quarry area — and to have quantity and quality verified at the production lot level rather than accepting market commentary. Trade names for this material include Star Galaxy, Galaxy granite and Ongole Galaxy; because "Galaxy" is applied loosely in the market, confirm against a physical sample rather than the name.

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African Black Granite: Multiple Origins, Verify by Sample

Buyers evaluating African blacks run into a documentation gap, and it is worth being straightforward about it rather than dressing it up.

What is documented is this: South Africa and Zimbabwe are among the origins producing material sold under the name "Absolute Black", alongside India and China. That single fact carries most of the useful information available. The names used in the trade for African black stone do not map reliably to a single quarry or deposit, and origin is multiple — the same category-name problem that affects Absolute Black globally.

The practical consequence for procurement is a discipline rather than a fact:

• Treat every African black name as a category label, in the same way you would treat "Absolute Black" or "China Black".
• Ask for the quarry location, the district and the rock type before discussing price. A supplier who cannot name the deposit is selling you an appearance.
• Verify by physical sample from the production lot. Because the naming does not pin down origin, the sample and the batch documentation are the evidence that carries the order.
• Write the acceptance criteria into the contract — colour against a retained sample, grain and fleck characteristics, thickness tolerance, and the physical properties you require.

Where a name cannot be tied to a deposit, the sample carries the entire specification. That is the takeaway for this origin group.

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Comparing Black Granite Types: The Five Variables That Matter

When two quotations both say "black granite" and the prices differ, the difference usually sits in one of five places. These are the variables to compare, because these are the ones you can specify, test and hold a supplier to.

1. Hardness

Hardness is the first thing to pin down. The reported values across this guide run from approximately 4.5 for Black Galaxy, through 6–7 for Absolute Black, to approximately 7 for Shanxi Black — with G684 reported below the hard granite blacks.

Why it matters commercially, in order of when it bites:

• Before the order — tooling, cutting speed and polishing time differ with hardness, and a fabricator pricing work on the wrong assumption absorbs the difference.
• At installation — edge profiles, cut-outs and drilled holes behave differently across the hardness range.
• In service — scratch resistance is the visible consequence, and it is where a hardness mismatch becomes a customer complaint rather than a cost line.

Read the Mohs figures as what they are: a comparative scratch-hardness scale. They rank materials against each other; they do not by themselves predict wear in a specific service environment.

2. Density

Density figures in this guide: Shanxi Black at 2.9–3.2 g/cm³, Absolute Black at approximately 2,800–3,000 kg/m³, and G684 at a quoted bulk density of 2.86.

For an importer, density has one dominant commercial use: freight. Dense black stone reaches container payload limits sooner than a lighter material, which means weight, rather than volume, is commonly the binding constraint on how much fits. Get the density on the right basis before you build a loading plan around a figure.

Two cautions. First, basis matters — G684's figure is given as a bulk density while the others are quoted as density in g/cm³, and those are not necessarily the same measurement. Second, typical is not batch — a supplier quoting a typical density is telling you what the material usually does, not what your container did. Where the number carries commercial weight, ask for the batch figure and the basis it was measured on.

3. Water Absorption

One absorption range is documented in our verified data: Absolute Black at approximately 0.05–0.30%, and it is quoted as a range because sources differ.

Absorption is the variable that governs how a black stone behaves around liquids — staining risk, sealing requirements, and performance in wet or freeze-thaw conditions. The width of that range is the useful information: it means the number is deposit- and batch-dependent rather than a fixed material constant.

The buyer's move is to stop treating absorption as a marketing number and start treating it as an acceptance criterion. State the value you will accept, state the test standard, and require the batch result. Industry ranges exchanged between buyer and seller settle nothing.

4. Crystal Structure and Grain

This is the variable that decides what the finished surface actually looks like, and it is the one most often left unstated.

• Absolute Black — fine to medium grained, ophitic; no visible crystal boundaries after polishing, producing a uniform mirror-black field.
• Shanxi Black — fine-grained and massive, with the deposit sorted into 大花 / 中花 / 细花 grain grades by crystal size. Mid and fine grain material is generally the more sought after.
• Black Galaxy — the grain is dominated by iron-rich enstatite (bronzite) flecks; the grain is the product.

Two projects can both specify "polished black granite" and require entirely different surfaces. A uniform black field and a grained black are different buying decisions, and the difference lives in the crystal structure, not in the name. On large elevations and matched installations, order samples spanning the block rather than a single small piece — grain size varies within a deposit, and one small sample is weak evidence of what the full lot will look like.

5. Yield and Available Formats

Yield determines what formats are realistically available and what they cost.

Black Galaxy is the clear case: only 30–40% of production reaches large gang-saw size above 2.40 m × 1.20 m × 1.00 m. If your project needs large matched slabs, you are buying from a minority of output and should plan price and lead time accordingly.

For the Chinese materials, the supply picture is different in kind. Shanxi Black's reserve of 193 million m³ against block output of approximately 35,000 m³ per year describes a deep deposit with a restrained extraction rate — relevant when planning repeat orders. G684's quarry footprint of approximately 0.21 km², roughly 800 m by 450 m, describes a compact, delimited deposit rather than an open-ended one, and its consolidation from 348 workshops to 28 companies plus 2 deep-processing enterprises changed the structure of who supplies it.

Yield and supply structure decide whether your format is available at all. Establish that before the price negotiation, not during it.

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Mohs Hardness Comparison: The Numbers Side by Side

Read the table as a ranking of reported values, not as a warranty. Two entries are worth flagging for how a buyer should use them.

The G684 entry has no number, and that is deliberate. The documented fact is that its hardness is lower than Shanxi Black and other hard granite-type blacks such as Fengzhen Black. Inventing a figure to fill the cell would be worse than leaving it empty, and a supplier who volunteers a precise Mohs number for G684 should be asked for the test basis.

The Black Galaxy entry is the one that changes buying decisions. A reported hardness of approximately 4.5 against a granite band of 6–7 is not a rounding difference. It is the difference between a material that resists scratching across years of service and one that needs a different conversation about where it goes and how it is maintained.

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Density and Water Absorption Compared

Two blank cells in this table are the honest result of a fact-checked approach, and they carry a lesson worth more than filled-in numbers would. Published property tables for black stone circulate widely and are frequently copied from one another without a stated test basis. A buyer who needs a density figure for a freeze-thaw specification, or an absorption figure for a sealed countertop, should get it from a batch test rather than from a datasheet that cannot say where its numbers came from.

For freight planning, the operational point stands: density converts your order into weight, and weight is commonly what fills a container of black stone before volume does. Get the figure on a known basis, from the material you are actually shipping, and build the loading plan from that.

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Reading Supplier Claims: Four Places Buyers Get Misled

The naming problems in this market are not usually fraudulent. They are commercial shorthand that has drifted away from the underlying facts, and a buyer who can spot the drift can price and specify around it.

1. Single-origin claims. You may see material marketed on the basis that one region is the sole source of a particular black. Our verified sources document otherwise: material sold as "Absolute Black" is produced in India, South Africa, Zimbabwe and China, and quality varies by quarry. A claim of exclusive origin should be treated as marketing rather than as fact, unless the supplier names the quarry and district and stands behind it in the contract.

2. Conflicting production figures. Volume and tonnage numbers for some black varieties conflict between published sources — in the case of Black Galaxy, substantially so. Where sources conflict at that level, the responsible position is to quote no figure at all and to verify quantity at the production lot level. A buyer should be cautious of any supplier who offers a confident production number that other sources do not support.

3. Trade names presented as specifications. "Black granite" is the umbrella term permitted by ASTM C119 for dark igneous rocks including dolerite, basalt and gabbro. "Absolute Black" is a category name covering several countries of origin. "China Black" is a national label applied to a Hebei material. None of these names constrains what you will receive. When a name is doing the work that a specification should be doing, the order is unprotected.

4. Aliases presented as alternatives. Shanxi Black, 太白青, 帝王黑 and Dynasty Black are names for one Hunyuan material; Star Galaxy, Galaxy granite and Ongole Galaxy are names for one Andhra Pradesh material. A buyer comparing them as if they were four different stones, or paying a premium for one name over another, is buying a label rather than a material.

The rule that covers all four cases: separate what the name asserts from what the sample and the test data assert. The name asserts nothing enforceable. The retained sample and the batch documentation assert things you can inspect, accept or reject.

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How to Write a Black Granite Purchase Order

Most black stone disputes trace back to a purchase order that described the material by name and nothing else. The following items convert a name into an order that can be enforced at the port.

Identify the material by origin and rock type, not just by trade name.

• Shanxi Black: "Shanxi Black, gabbro-diabase, quarried at Hunyuan, Shanxi Province."
• G684: "G684 Fuding Black, basalt, quarried at Bailin Town, Fuding, Fujian Province."
• Absolute Black: "Absolute Black, dolerite, quarried in [district], Karnataka, India."
• Black Galaxy: "Black Galaxy, gabbric anorthosite, quarried at Chimakurthi, Prakasam District, Andhra Pradesh, India."

Naming the rock type alongside the trade name costs nothing and removes the entire category confusion at the heart of this guide. It also forces the supplier to be specific about origin at the quotation stage.

Attach and retain a physical reference sample. Both parties hold a sealed piece. The order states that delivered material must match the retained sample. This is the single most effective control in black stone procurement, because colour and grain are the properties buyers most often find changed on arrival and the least often specified in writing.

State the grade using observable criteria. Where a grading system exists — Shanxi Black's A/B grade and its 大花 / 中花 / 细花 grain classification — name the grade and define it: base colour, crystal or grain size, fleck density where relevant, and a maximum defect count. The letter or the Chinese grain term on its own does not define what will be delivered; the observable criteria do.

Specify the finish per item. Polished, honed and other finishes read differently and are not interchangeable. State the finish for each line item rather than once for the order.

State thickness with a tolerance, and state where it is measured. Thickness checked at the slab edge can differ from thickness at the centre. If the tolerance is ±1 mm, say so, and say where the measurement is taken.

State the physical properties you require, with the test standard and the batch basis. For each property — density, water absorption, and any others your application depends on — state the value you will accept, the standard it is to be tested to, and whether a batch certificate is required. Where you have a range rather than a point value, state the range. And remember the basis trap: a bulk density is not the same measurement as a density quoted in g/cm³, so an order that does not specify the basis leaves the comparison open.

State the required slab format and the minimum acceptable size. This matters most where yield is constrained. Black Galaxy's 30–40% yield at large gang-saw size means a large-format requirement competes for a minority of output; the order should state the minimum slab dimensions you will accept so the constraint is visible in the price and the lead time.

State the packing and loading plan, and check it against container payload. Dense black stone commonly hits payload before volume. Ask for the loaded weight, not just the cubic measurement.

Nominate the pre-shipment inspection, and route the report to you. State who inspects, what is checked, and that the inspector reports to the buyer rather than to the supplier. An inspection that reports to the party being inspected is not a control.

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Pre-Shipment Inspection Checklist for Black Stone

The following checklist is written to be handed to an inspector. Each item is something that can be observed or measured, which is the test of whether it belongs in an inspection at all.

1. Identity against the retained sample. Photograph the sealed reference sample next to production slabs under the same lighting, and include the photograph in the report. Black stone is unusually sensitive to lighting angle and to whether the surface is wet or dry; an inspection report without the reference in frame cannot be assessed afterwards.

2. Colour and grain consistency. Check base colour and grain against the approved criteria. For the Chinese materials, confirm the delivered grain grade — 大花, 中花 or 细花. For Black Galaxy, assess fleck density and distribution, since the flecks are the material's defining feature.

3. Surface condition. Check polish uniformity across the slab face, and look for visible defects. Surface quality on black stone is unforgiving: a uniform black field shows up any variation that a patterned stone would hide.

4. Dimensions and tolerance. Measure thickness at the slab edges and at the centre, and measure plan dimensions and squareness. Compare against the tolerance stated in the order. Edge-only measurements can pass a slab that would fail a centre check.

5. Slab format for large-format orders. Where the project needs large matched slabs — and particularly for Black Galaxy, given the yield constraint — measure the actual slab dimensions and record them. Do not accept nominal sizes in place of measured ones.

6. Quantity and load. Verify piece counts against the order, confirm the packing plan, and confirm the loaded weight against the container payload figure you planned around.

7. Batch documentation. Collect the test reports for the properties stated in the order, and check that each reports the standard it was tested to and whether the values are typical or batch-tested. A property table that does not name a standard does not support an acceptance decision.

8. Report routing. Confirm the report comes to the buyer. This sounds administrative and is not: it is the difference between an inspection and a formality.

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Black Granite Buyer FAQ

Is black granite real granite?

Sometimes it is, and sometimes it is not — and the term is used in both cases. True granite is composed of quartz, light-coloured feldspar and mica, and is typically light in colour. Most stone traded as black granite is a dark mafic igneous rock — dolerite (diabase), basalt or gabbro. ASTM C119 permits these dark igneous rocks to be sold under the name "black granite", so the term is a trade classification rather than a mineralogical claim [source: stonecrestinternational.com]. The two naming systems can both be correct and still mean different things. The practical answer is to name the rock type in your order alongside the trade name.

Which is harder, Shanxi Black or Black Galaxy?

As reported, Shanxi Black sits at approximately 7 on the Mohs scale and Black Galaxy at approximately 4.5. Shanxi Black is the harder of the two in scratch terms, and the gap is large. That difference affects where each material is suitable, how it is processed, and how it wears in service.

Is G684 a granite?

No. G684 Fuding Black is a basalt, and this site lists it as such. It is sold into the same black stone market as the granite-type blacks and is offered against them in the same quotations, but it is a different rock type, and its reported hardness is lower than that of Shanxi Black and other hard granite-type blacks such as Fengzhen Black.

Why does the same stone have so many names?

Trade names are commercial rather than regulated, and they often come from appearance, marketing or the port of shipment rather than from the deposit. Shanxi Black also moves as 太白青, 帝王黑 and Dynasty Black. Black Galaxy also moves as Star Galaxy, Galaxy granite and Ongole Galaxy. When names multiply like this, ask for the quarry location and the rock type — those are the identifiers that stay attached to the material.

Is Absolute Black a single-origin Indian material?

No. "Absolute Black" is a category name, not a single-origin product. India (Karnataka), South Africa, Zimbabwe and China all produce material sold under that name, and quality varies by quarry. Claims that one region is the sole source should be treated with caution.

What is the practical difference between Chinese and Indian blacks?

From the documented data, the clearest differences are hardness and density. Shanxi Black (approximately 7) and Absolute Black (6–7) sit within or at the top of the granite hardness band, while Black Galaxy at approximately 4.5 sits clearly below it. On density, Shanxi Black is quoted at 2.9–3.2 g/cm³ and Absolute Black at approximately 2,800–3,000 kg/m³ — a freight consideration for container planning. Physical properties differ between individual varieties within each origin group as well, so compare material to material rather than country to country.

How should I compare two black samples properly?

Compare them on the five variables that matter: hardness, density, water absorption, crystal structure and grain, and yield or available format. Do not compare them on photographs. For every number you are given, ask for the test basis and whether it is a typical value or a batch result. Where you are matching an existing installation, view physical samples side by side under the same light.

Does "A grade" mean the same thing from every supplier?

The letter alone does not define the criteria, so it should not be relied on by itself. Shanxi Black carries an A/B grade alongside the 大花 / 中花 / 细花 grain classification, and A-grade material is commonly directed to monument work. But what a given supplier calls grade A is not a harmonised industry standard, and the term should be backed by observable criteria in the order — base colour, grain size, defect limits — rather than left as a letter.

Which black should I choose for exterior paving or heavy-use surfaces?

A name cannot answer that. Match the material's reported properties to the service condition. A material with a reported hardness well below the granite band behaves differently under abrasion than one at the top of it, and water absorption governs how the stone handles wet and freeze-thaw conditions. Specify the properties you need, test the batch, and state the value you will accept.

What should I do when a supplier cannot name the quarry?

Treat it as a category label and verify by physical sample. This is the standard situation with African black material, where the names in the trade do not map reliably to a single deposit and origin is multiple. Ask for quarry location, district and rock type; verify by sample from the production lot; and write the acceptance criteria into the contract. Where the name cannot be tied to a deposit, the sample carries the whole specification.

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Summary

The black stone market runs on names, and the names do not carry the information buyers need. ASTM C119 permits dark igneous rocks — dolerite, basalt, gabbro — to be sold as "black granite", so the term describes a commercial category rather than a rock. "Absolute Black" has become a category name covering production in India, South Africa, Zimbabwe and China. Shanxi Black, 太白青, 帝王黑 and Dynasty Black are four names for one Hunyuan gabbro-diabase. G684 Fuding Black is a basalt, not a granite, and its reported hardness is lower than the hard granite-type blacks. Black Galaxy reports approximately 4.5 on the Mohs scale, clearly below the granite band of 6–7.

What a buyer can rely on is narrower and considerably more useful. Shanxi Black: Hunyuan, gabbro-diabase, Mohs approximately 7, density 2.9–3.2 g/cm³, graded A/B and by grain into 大花 / 中花 / 细花. G684 Fuding Black: Bailin, Fuding, basalt, bulk density 2.86, alkali resistance 99.93–99.96%, hardness below Shanxi Black. Absolute Black: Karnataka, dolerite, Mohs 6–7, density approximately 2,800–3,000 kg/m³, absorption approximately 0.05–0.30%. Black Galaxy: Chimakurthi, gabbric anorthosite, gold flecks of iron-rich enstatite, Mohs approximately 4.5, with 30–40% of production reaching large gang-saw size.

The method that follows from all of it is short. Name the rock type and the quarry location in the order, not just the trade name. Attach a retained sample both parties hold. Define grade by observable criteria. State each physical property with its test standard and whether it is a batch result. Nominate the pre-shipment inspection and route the report to yourself. Do those things and the name on the quotation stops being the specification — which is where it belongs.

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Related Reading

• Granite vs Marble vs Quartz — how the major countertop and cladding materials compare on hardness, porosity and maintenance, for buyers specifying across material families.
• Black Granite Uses — where black stone is specified in practice: monuments, cladding, paving, countertops and architectural components.
• Black Granite History and Origins — the quarrying history behind the names, including the Shanxi deposits and the Fuding consolidation.
• Shanxi Black Granite — the Hunyuan gabbro-diabase in detail: A/B grading, grain classes, and how it differs from Absolute Black.