Green Slag Glass
Cullet (Amorphous Silicon Dioxide with impurities)
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Green Slag Glass
Cullet (Amorphous Silicon Dioxide with impurities)
Quartz Crystal
Silicon Dioxide (SiO2)
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Quartz (specifically Milky or Clear Chunk)
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
Sandstone
Clastic sedimentary rock (primarily SiO2)
Olivine (Peridot when gem-quality)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Quartz
Silicon Dioxide (SiO2)
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 based)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Concrete Fragment
Hardened Portland Cement Composite
Sandstone
Arenite (SiO2 based)
Amethyst Geode
Silicon Dioxide with impurities (SiO2)
Quartz Conglomerate
Quartz Conglomerate (clastic sedimentary rock)
Amethyst
Amethyst (SiO2 with iron impurities)
Banded Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
Diamond
Carbon (C)
Quartz
Quartz (Silicon Dioxide, SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Limestone
Calcium Carbonate (CaCO3)
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Quartz (Milky/Granular)
Silicon Dioxide (SiO2)
Chert (Flint Nobule)
Silicon Dioxide (SiO2)
Black Marble
Recrystallized Carbonate Rock (CaCO3)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 with assorted lithic fragments)
Olivine (Peridotite)
Olivine Group; (Mg, Fe)2SiO4
Black Sapphire (Basaltic Blue Sapphire)
Corundum (Al2O3)
Ferruginous Siltstone or Mudstone
Ferruginous Siltstone / Goethitic Sandstone
Peridot (Olivine)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Amber
Succinite (C10H16O)
Conglomerate
Conglomerate (clastic sedimentary rock)
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Topaz
Topaz (Al2SiO4(F,OH)2)
Biotite Mica in Host Rock
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Banded Chert
Microcrystalline Quartz (SiO2)