Amethyst
Amethyst (Silicon Dioxide, SiO2)
Category
Browse mineralogical specimen specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Gabbro with Quartz Vein
Gabbro (mafic intrusive igneous rock)
Ferruginous Sandstone (with possible Epidote/Chlorite coloring)
Sandstone (SiO2 dominated with Fe2O3 staining)
Gneiss (specifically Micaceous Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
Amazonite in Matrix
Potassium Feldspar (Microcline), KAlSi3O8
Jasper (Multi-colored) / Sea Glass Slag
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Quartzite
Quartzite (SiO2)
Dendritic Jasper (Bumblebee like Agate)
Silicon Dioxide with inclusions (SiO2)
Citrine (Iron-stained Quartz)
Silicon Dioxide (SiO2)
Chert / Microcrystalline Quartz
Chert (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Chalcedony Geode (Botryoidal Agate)
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Jasper (with Agate/Chalcedony inclusions)
Silicon Dioxide (SiO2)
Gneiss
Foliated Metamorphic Gneiss
Gneiss (Metamorphosed Pebble)
Gneiss with Quartz/Feldspar banding
Quartzite (River Pebble)
Metamorphosed Quartz Sandstone (SiO2)
Quartzite Pebble
Quartzite (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Orange Calcite
Calcium Carbonate (CaCO3)
Gneiss
Gneiss (High-grade metamorphic rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Basalt with Iron Oxidation
Mafic Igneous Basalt
Quartzite
Metamorphosed Sandstone (Mainly SiO2)
Milky Quartz (Water-worn pebble)
Quartz (Silicon Dioxide, SiO2)
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Ethiopian Opal (Welo Opal)
Hydrated Amorphous Silica (SiO2·nH2O)
Goniatite Fossil
Goniatitida (Order), fossilized in limestone/calcite (CaCO3)
Yellow Quartz (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
Citrine
Silicon Dioxide (SiO2) with iron impurities
Amethyst (Geode)
Silicon Dioxide (SiO2) with iron impurities
Fossilized Oyster (Devil's Toenail)
Gryphaea (extinct genus of bivalve mollusks)
Blue Calcite
Calcium Carbonate (CaCO3)
Clear Quartz
Silicon Dioxide (SiO2)
Dinosaur Bone (Gembone)
Silicified Dinosaur Bone (SiO2 replacing organic tissue)