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Black Rocks, Minerals & Gemstones

Found a black rock and want a name for it? This guide lists all 91 black rocks, minerals and gemstones in the StoneSnap database, from common finds like Obsidian, Basalt, and Anthracite to collector specimens.

Color alone rarely identifies a specimen, so start with luster (46 glassy, 16 dull or earthy, 16 metallic, and 13 waxy, silky or pearly in this list), then check hardness with a scratch test and streak color. Each card links to a full identification guide with tests, look-alikes and value.

Also browse:White rocksGray rocksBrown rocksGreen rocksPink rocksYellow rocksRed rocksBlue rocksPurple rocksOrange rocksClear rocksMulticolored rocks

Metallic black rocks (16)

Anthracite specimen: black and steel gray metamorphic rockAnthraciteMohs 2.5 · submetallic · commonChalcocite specimen: blackish lead-gray and black mineralChalcociteMohs 2.5–3 · Metallic · commonChromite specimen: black and brownish black mineralChromiteMohs 5.5 · Metallic to submetallic · commonFranklinite specimen: black and brownish black mineralFrankliniteMohs 5.5–6.5 · Metallic to submetallic · commonGraphite specimen: black and steel-gray mineralGraphiteMohs 1–2 · Metallic to dull/earthy · commonIlmenite specimen: black and iron-black mineralIlmeniteMohs 5.5 · metallic · commonMagnetite specimen: black and iron-black mineralMagnetiteMohs 5.5–6.5 · Metallic to submetallic/dull · commonPyrolusite specimen: black and steel gray mineralPyrolusiteMohs 6.25 · metallic · commonShungite specimen: black and dark gray sedimentary rockShungiteMohs 3.5 · submetallic · uncommonHematite specimen: metallic gray and black mineralHematiteMohs 6 · metallic · commonBanded Iron Formation specimen: red and reddish brown sedimentary rockBanded Iron FormationMohs 5–7 · Vitreous (chert bands) to metallic/dull (iron oxide bands) · commonCassiterite specimen: brown and black mineralCassiteriteMohs 6–7 · Adamantine to submetallic · commonCopper specimen: copper red (fresh) and brown to green-black (tarnished) mineralCopperMohs 2.5–3 · Metallic · commonCovellite specimen: indigo blue and blue-black mineralCovelliteMohs 1.5–2 · Metallic to submetallic/resinous · commonCuprite specimen: red and dark red mineralCupriteMohs 3.5–4 · Adamantine to submetallic or earthy · commonSterling Silver specimen: silver and white silver metalSterling SilverMohs 2.7 · metallic · common

Glassy black rocks (46)

Obsidian specimen: black and brown igneous rockObsidianMohs 5.5 · vitreous · commonRainbow Obsidian specimen: black with rainbow sheen and purple igneous rockRainbow ObsidianMohs 5.5 · vitreous · uncommonAugite specimen: black and dark green mineralAugiteMohs 5.5–6 · Vitreous to resinous · commonBiotite specimen: black and dark brown mineralBiotiteMohs 2.5–3 · Vitreous to pearly (splendent on cleavage) · commonCoal specimen: black and brownish black sedimentary rockCoalMohs 1–2.5 · Dull (lignite) to vitreous (anthracite) · commonFlint specimen: black and dark gray sedimentary rockFlintMohs 6.5–7 · Waxy to dull, glassy on fresh fracture · commonHornblende specimen: black and dark green mineralHornblendeMohs 5–6 · Vitreous to silky · commonOnyx specimen: mineralOnyxMohs 6.5–7 · Waxy to vitreous · commonSchorl specimen: black and bluish black mineralSchorlMohs 7 · vitreous · commonSnowflake Obsidian specimen: black and black and white igneous rockSnowflake ObsidianMohs 5.5 · vitreous · commonTourmaline specimen: black and green mineralTourmalineMohs 7–7.5 · Vitreous · commonDiamond specimen: colorless and yellow gemstoneDiamondMohs 10 · adamantine · legendaryOpal specimen: white and black gemstoneOpalMohs 5.5 · vitreous · uncommonSpinel specimen: red and pink gemstoneSpinelMohs 8 · vitreous · uncommonMarble specimen: white and gray metamorphic rockMarbleMohs 3.5 · vitreous · commonGranite specimen: pink and gray igneous rockGraniteMohs 6.5 · vitreous · commonSmoky Quartz specimen: brown and gray crystalSmoky QuartzMohs 7 · vitreous · commonKyanite specimen: blue and green mineralKyaniteMohs 5 · vitreous · uncommonRhodonite specimen: pink and rose mineralRhodoniteMohs 6 · vitreous · uncommonSlag Glass specimen: blue and green materialSlag GlassMohs 5.5 · vitreous · commonLarvikite specimen: dark gray and blue gray igneous rockLarvikiteMohs 6 · vitreous · commonActinolite specimen: green and dark green mineralActinoliteMohs 5–6 · Vitreous to silky · commonAegirine specimen: dark green and black mineralAegirineMohs 6–6.5 · Vitreous · commonAlmandine specimen: deep red and reddish brown mineralAlmandineMohs 7–7.5 · Vitreous to resinous · commonAndesite specimen: gray and dark gray igneous rockAndesiteMohs 5–6 · Dull groundmass with vitreous phenocrysts · commonAndradite specimen: yellow-green (demantoid) and brown mineralAndraditeMohs 6.5–7 · Vitreous to resinous/adamantine · commonCharoite specimen: lilac and purple mineralCharoiteMohs 5–6 · Vitreous to pearly/silky · commonChlorite specimen: green and dark green mineralChloriteMohs 2–2.5 · Vitreous to pearly · commonDiopside specimen: light to dark green and white mineralDiopsideMohs 5.5–6.5 · Vitreous · commonDiorite specimen: salt-and-pepper gray and dark gray igneous rockDioriteMohs 6–7 · Vitreous to dull (granular) · commonEpidote specimen: pistachio green and yellowish green mineralEpidoteMohs 6–7 · Vitreous · commonGabbro specimen: dark gray and black igneous rockGabbroMohs 5–6.5 · Dull to vitreous (in crystals) · commonGlauconite specimen: green and dark green mineralGlauconiteMohs 2–3 · Dull to earthy, slightly vitreous · commonGneiss specimen: gray and pink metamorphic rockGneissMohs 6–7 · Vitreous to glimmering (mica-rich bands) · commonGoethite specimen: brown and yellowish brown mineralGoethiteMohs 5–5.5 · Adamantine to dull/earthy, silky · commonJadeite specimen: green and white gemstoneJadeiteMohs 6.75 · vitreous · rareMigmatite specimen: pink and black and light and dark layered metamorphic rockMigmatiteMohs 5–7 · Vitreous to dull (banded) · commonMoss Agate specimen: colorless and white gemstoneMoss AgateMohs 6.75 · vitreous · commonPeridotite specimen: green and dark green igneous rockPeridotiteMohs 5.5–7 · Vitreous (olivine and pyroxene grains) · commonQuartz specimen: colorless and white crystalQuartzMohs 7 · Vitreous, greasy on fracture surfaces · commonRutile specimen: reddish brown and black mineralRutileMohs 6.5 · adamantine · commonSchist specimen: silver-gray and golden (mica-rich) metamorphic rockSchistMohs 2.5–7 · Vitreous to silky/glittery (mica-rich) · commonScoria specimen: dark red and black igneous rockScoriaMohs 5–6 · Dull, glassy · commonShale specimen: gray and black sedimentary rockShaleMohs 2–3 · Dull to earthy (slightly sub-vitreous if micaceous) · commonStaurolite specimen: reddish brown and brown mineralStauroliteMohs 7.25 · vitreous · uncommonTitanite specimen: green and yellow mineralTitaniteMohs 5.5 · adamantine · uncommon

Waxy, silky or pearly black rocks (13)

Jet specimen: black and dark brown gemstoneJetMohs 3 · waxy · uncommonPearl specimen: white and cream gemstonePearlMohs 3 · pearly · uncommonDendritic Agate specimen: white and gray mineralDendritic AgateMohs 7 · waxy · commonDalmatian Jasper specimen: cream and white mineralDalmatian JasperMohs 7 · waxy · commonGreenschist specimen: green and gray green metamorphic rockGreenschistMohs 4.5 · silky · commonAnorthosite specimen: white and gray igneous rockAnorthositeMohs 6 · pearly · commonBlueschist specimen: blue and blue gray metamorphic rockBlueschistMohs 5.5 · silky · uncommonMylonite specimen: gray and black metamorphic rockMyloniteMohs 5.5 · silky · uncommonChert specimen: gray and white sedimentary rockChertMohs 6.5–7 · Waxy to dull · commonPhyllite specimen: silvery gray and greenish gray metamorphic rockPhylliteMohs 2.5–4 · Silky to satiny (sericite/chlorite sheen) · commonSerpentine specimen: green and yellowish green mineralSerpentineMohs 3.5 · greasy · commonSerpentinite specimen: green and dark green metamorphic rockSerpentiniteMohs 2.5–4 · Greasy, waxy, silky · commonSphalerite specimen: brown and black mineralSphaleriteMohs 3.75 · resinous · common

Dull or earthy black rocks (16)

Basalt specimen: black and dark gray igneous rockBasaltMohs 6 · dull · commonAmphibolite specimen: black and dark green metamorphic rockAmphiboliteMohs 5.5 · dull · commonNorite specimen: black and dark gray igneous rockNoriteMohs 6 · dull · commonSlate specimen: gray and black metamorphic rockSlateMohs 3.5 · dull · commonIronstone specimen: brown and red brown sedimentary rockIronstoneMohs 4 · dull · commonBasaltic Andesite specimen: dark gray and black igneous rockBasaltic AndesiteMohs 6 · dull · commonGraywacke specimen: dark gray and greenish gray sedimentary rockGraywackeMohs 6 · dull · commonHornfels specimen: gray and black metamorphic rockHornfelsMohs 6 · dull · commonIgnimbrite specimen: tan and pink igneous rockIgnimbriteMohs 6 · dull · commonSkarn specimen: green and brown metamorphic rockSkarnMohs 5.5 · dull · uncommonMetaconglomerate specimen: gray and white metamorphic rockMetaconglomerateMohs 6.5 · dull · uncommonMonzonite specimen: gray and pink igneous rockMonzoniteMohs 6 · dull · commonTonalite specimen: white and gray igneous rockTonaliteMohs 6 · dull · commonPhonolite specimen: gray and greenish gray igneous rockPhonoliteMohs 6 · dull · uncommonTephrite specimen: dark gray and black igneous rockTephriteMohs 6 · dull · uncommonMudstone specimen: gray and brown sedimentary rockMudstoneMohs 2–3 · Dull, earthy · common

Frequently asked questions

What is a black shiny rock most likely to be?

Shiny black rocks are usually Obsidian, Anthracite, Augite, and Biotite. Check whether the shine is metallic or glassy, then test hardness against glass to narrow it further.

How do I identify a black rock at home?

Rinse it, look at the luster and grain under good light, scratch it against glass and a steel knife to bracket its Mohs hardness, and rub it on unglazed porcelain to see the streak color. Compare the results with the black candidates on this page, or scan it with the StoneSnap app for an instant match.

Are black rocks valuable?

Most black rocks are common and worth a few dollars as specimens, but gem-grade material such as Diamond, Pearl, and Opal can be worth far more. Each page lists a typical value range.

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