Greenstone
Chlorite schist / Meta-basalt
metamorphic
Category
Organic Gemstone (Often Associated With Sedimentary Sequences)
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Specular Hematite with Pyrite
Iron Oxide (Fe2O3) with Iron Sulfide (FeS2)
mineral
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2) with Iron Oxide impurities
sedimentary
Turquoise (Rough)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
mineral
Chalcedony (specifically Agate or Common Opal variety)
Cryptocrystalline Silica (SiO2)
mineral
Limestone with Bitumen/Chert
Calcite (CaCO3) containing organic hydrocarbons
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
mineral (silicate-replaced organic material)
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Red Jasper (Mahogany Obsidian variant similarity)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Peach Moonstone
Orthoclase Feldspar (KAlSi3O8)
mineral
Jasper
Jasper (Silica/Silicon Dioxide, SiO2)
sedimentary
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Epidote in Matrix (Dragon Stone variant)
Epidote with Quartz/Feldspar (Ca2(Al,Fe)3(SiO4)3(OH))
metamorphic
Quartzite
Quartzite (SiO2)
Metamorphic
Yellow Jasper
Jasper (SiO2) with iron hydroxide inclusions
sedimentary
Carnelian (a variety of Chalcedony)
SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Sandstone Pebble
Arenite (primarily SiO2)
sedimentary
Labradorite
(Ca, Na)(Al, Si)4O8 (Plagioclase Feldspar)
mineral
Yellow Aventurine (Quartz Quartzite)
Silicon Dioxide with Mica inclusions (SiO2 + KAl2(AlSi3O10)(OH)2)
Metamorphic
Bixbyite on Rhyolite
Bixbyite (Mn2+,Fe3+)2O3
mineral
Cuprite
Cuprite (Copper(I) oxide, Cu2O)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Malachite
Copper(II) carbonate hydroxide, Cu2CO3(OH)2
mineral
Desert Rose
Gypsum (CaSO4·2H2O) or Barite (BaSO4) with Sand inclusions
mineral
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Quartz with Pyrite
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
mineral
Unakite
Epidotized Granite (SiO2 with Ca2(Al, Fe)3(SiO4)3(OH))
metamorphic
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Mineral, Organic Gemstone
Jasper
Silicon Dioxide (SiO2)
sedimentary
Red Tiger's Eye beads
Tiger's Eye (variety of Chalcedony, SiO2)
Mineral / Gemstone (variety of Quartz)
Amber
Succinite (with approximate formula C10H16O)
mineraloid
Agate (Moss or Dendritic Agate)
Chalcedony (Silicon Dioxide, SiO2)
mineral
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Chert (and Flint)
Silicon Dioxide (SiO2)
sedimentary
Fossilized Shark Tooth
Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Jasper (Mookaite style)
Silicon Dioxide (SiO2) with iron and manganese inclusions
sedimentary
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral