Selenite
Gypsum (CaSO4·2H2O), specifically the crystalline variety Selenite
Category
Browse mineral (specifically a cryptocrystalline variety of quartz) specimens identified by the Rock Identifier community.
Selenite
Gypsum (CaSO4·2H2O), specifically the crystalline variety Selenite
Chert (or Flint)
Chert (microcrystalline or cryptocrystalline quartz, SiO2)
Agate (Carnelian Agate with Quartz Matrix)
Silicon Dioxide (SiO2)
Tumbled brown chalcedony (likely jasper or agate)
Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining
Polished orbicular jasper (likely ocean jasper)
Jasper, a microcrystalline variety of quartz (SiO₂), with iron-oxide and other mineral inclusions
Red Jasper
Microcrystalline Quartz (SiO2) with iron oxide impurities
Tumbled banded agate (likely blue lace agate)
Microcrystalline quartz, SiO₂ (chalcedony variety)
Red jasper cobble
Jasper, an opaque microcrystalline quartz variety (SiO₂), colored chiefly by iron oxides
Tumbled yellow jasper (likely silicified/iron-stained chert)
Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides and darker inclusions
Chert (Flint)
Silicon Dioxide (SiO2)
Specular Hematite (Specularite)
Iron(III) oxide (Fe2O3)
Banded Agate (Tumbled)
Agate (Variety of Chalcedony/Quartz), SiO2
Tumbled milky quartz pebble
Quartz (SiO₂), cryptocrystalline to coarse microcrystalline variety
Chalcedony (Yellow Chert / Agate)
Quartz (Silicon Dioxide - SiO2)
Amazonite
Amazonite (KAlSi3O8, a variety of Microcline)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Quartz (likely Rose or Milky Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz with Matrix
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Smoky Quartz
Smoky Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Tumbled chalcedony (likely moss or gray agate)
Microcrystalline quartz, SiO₂; chalcedony/agate variety
Banded Agate
Agate (Cryptocrystalline Quartz, SiO2)
Quartz (likely Rose Quartz or Milky Quartz)
Silicon Dioxide (SiO2)
Tumbled jasper (likely brecciated or orbicular jasper)
Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral inclusions
Polished carnelian/chalcedony
Microcrystalline quartz (SiO₂), likely iron-stained chalcedony
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Tumbled chalcedony (likely agate or jasper)
Microcrystalline quartz, SiO₂ (chalcedony)
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
Sunstone (Feldspar variety)
Plagioclase Feldspar (Na,Ca)(Si,Al)3O8 with Hematite/Goethite inclusions
Chert (specifically Gray/Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Tumbled carnelian (orange chalcedony)
Carnelian, a microcrystalline variety of quartz (SiO₂)
Rhyolitic jasper / brecciated jasper
Silica-rich volcanic rock, chiefly microcrystalline quartz (SiO₂), with iron-oxide and clay/mineral impurities
Citrine
Silicon Dioxide (SiO2)
Smoky Quartz (with Iron Inclusions)
Silicon Dioxide (SiO2)
Jasper
Chalcedony (SiO2)