Petrified Wood
Silicified Wood (SiO2)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)
Dalmation Stone
Peralkaline Rock (mixed silicate minerals)
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
Pearl
Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)
Unakite
Epidotized Granite
Yellow Quartz (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)
Graphite
Graphite (Carbon, C)
Clear Quartz
Silicon Dioxide (SiO2)
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Black Veined Jasper (Spiderweb Jasper)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
White Quartz
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Shale with Plant Fossils / Carbonaceous Shale
Laminated Mudrock (Siliciclastic)
Carnelian Agate
Silicon Dioxide (SiO2)
Oak Wood (Wood Grain Pattern)
Quercus (genus)
Bituminous Coal
Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)
Conglomerate
Conglomerate
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Chert (Nodule / Geode fragment)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
Chert / River Pebble
Microcrystalline Silica (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Quartz Pebble)
Silicon Dioxide (SiO2)
Quartzite (specifically Milky Quartz variety)
Quartz (SiO2)
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
Chert (often referred to as Flint or Jasper)
Chalcedony (SiO2) - Silicon Dioxide
Red Jasper
Jasper (SiO2) with Hematite (Fe2O3) inclusions
Mookaite Jasper
Radiolarite (SiO2 with impurities)
Emerald with Matrix (Emerald in Mica Schist)
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock