Unakite
Epidotized Granite
metamorphic
Category
Organic Gemstone (Not A Rock Or Mineral)
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
mineral
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)
sedimentary
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
mineral
Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert Nodule (Fossiliferous Chert)
Microcrystalline Quartz (SiO2)
sedimentary
White Topaz
Aluminum Silicate Fluoride Hydroxide; Al2SiO4(F,OH)2
mineral
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
mineral
Pink Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O)
mineral
Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2)
sedimentary
Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
mineraloid
Quartz Geode
Silicon Dioxide (SiO2)
sedimentary
Sandstone
Arenite (primarily composed of SiO2)
sedimentary
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Sedimentary
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
mineral
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
sedimentary
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
mineral
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Carnelian and White Quartz Bracelet
Silicon Dioxide (SiO2) - specifically Carnelian (Chalcedony) and Rock Crystal/Snow Quartz
mineral
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Clear Quartz
SiO2 (Silicon Dioxide)
mineral
Milky Quartz (Quartz Vein)
Silicon Dioxide (SiO2)
mineral
Bamboo Leaf Jasper
Silicified Siltstone or Jasper (SiO2)
sedimentary
Amber
Succinite (formula varies, primarily C10H16O)
Mineraloid (Organic)
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
mineral
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
sedimentary
Jasper (Brown Iron-Rich Variety)
Silicon Dioxide (SiO2) with Fe2O3 (Iron Oxide/Crystalline Quartz)
sedimentary
Chert / Flint
Chert (Silicon Dioxide, SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
sedimentary
Emerald with Matrix (Emerald in Mica Schist)
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Amber
Succinite (fossilized resin)
mineral
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4 (Mineral) within Basalt (Rock)
igneous
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
sedimentary
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary