Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)
Category
Browse mineral (gemstone variety of beryl) specimens identified by the Rock Identifier community.
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz (Water-Worn Pebble)
Quartz (Silicon Dioxide, SiO2)
Quartz (Milky or Cloudy variety)
Silicon Dioxide (SiO2)
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Milky Quartz with Dendritic Inclusions
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Turquoise and Spiny Oyster (Heishi style beads)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Spondylus (Spiny Oyster shell)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Green Tourmaline (Verdelite)
Tourmaline Group; often Elbaite (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4) or Dravite (NaMg3Al6(BO3)3Si6O18(OH)4)
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite/Limonite)
Green Calcite (Onyx Marble)
Calcium Carbonate (CaCO3)
Jasper
Jasper (Silica/Quartz) - SiO2
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Milky Quartz (with potential inclusion)
Silicon Dioxide (SiO2)
Galena
Lead Sulfide (PbS)
Black Onyx
Onyx (Silicon Dioxide, SiO2)
Dyed Agate
Silicon Dioxide (SiO2) with synthetic dyes
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Greywacke (River Slikenside)
Greywacke (Lithic Sandstone)
Turquoise (with Hematite)
CuAl6(PO4)4(OH)8·4H2O
Diorite
Phaneritic plutonic rock (dominated by plagioclase feldspar and hornblende)
Almandine Garnet in Matrix
Almandine, Fe3Al2(SiO4)3
Snowflake Obsidian
Vitreous Volcanic Rock (Amorphous Silicate), SiO2
Fuchsite in Quartz
K(Al,Cr)2(AlSi3O10)(OH)2 in SiO2
Tiger's Eye
SiO2 (Pseudomorph of Quartz after Crocidolite)
Blue Lace Agate
Silicon dioxide (SiO2) - Chalcedony variety
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Rough Amber (likely Copal or immature Amber)
Organic gemstone / Succinite (if Baltic)
Baltic Amber (Butterscotch or Egg Yolk Variety)
Fossilized Tree Resin (Succinite); Approximate formula: C10H16O
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz (Common Milky Quartz)
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Milky Quartz
Silicon Dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Chert (often referred to as Flint or Jasper)
Chalcedony (SiO2) - Silicon Dioxide
Jasper
Silicon Dioxide (SiO2) with impurities
Jasper
Silicon dioxide (SiO2) with impurities