Unakite
Epidotized Granite
Category
Browse not a natural rock specimens identified by the Rock Identifier community.
Unakite
Epidotized Granite
Quartzite River Rock
Quartzite (primarily SiO2)
Obsidian / Volcanic Glass
Obsidian (principally SiO2, usually 70% or more)
Orange Calcite
Calcium Carbonate (CaCO3)
Fluorite (Rainbow Fluorite)
Fluorite (Calcium Fluoride, CaF2)
Fluorite
Calcium Fluoride (CaF2)
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
Dyed Blue Quartzite
SiO2 (Silicon Dioxide) with artificial colorants
Sandstone
Arenite (primarily SiO2)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Carnelian
Carnelian (Silicon Dioxide - SiO2 with iron oxide impurities)
Amethyst
Silicon Dioxide (SiO2)
Purple Banded Agate
Cryptocrystalline Quartz (SiO2)
Amethyst and Citrine (Quartz variants)
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Yellow Quartz Pebble (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Vesicular Basalt with Epidote
Vesicular Basalt (Mg, Fe)2SiO4 with Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite (Ochreous)
FeO(OH)·nH2O (Hydrated Iron Oxide)
Quartzite with Hematite staining
Quartzite (SiO2) with iron oxide inclusions
Quartzite (River Pebble)
Meta-quartzite (composed primarily of SiO2)
Red Coral
Corallium rubrum (for precious red coral), although other species like Corallium japonicum and Paracorallium are also used.
Opalite
Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)
Yellow Quartzite (River Pebble)
Quartzite (primarily Silicon Dioxide, SiO2)
Amethyst (Rough Quartz)
Silicon Dioxide (SiO2) with iron impurities
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
Quartz Druzy (on Matrix)
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2) - Ferric Iron impurities
Diamond
Diamond (pure Carbon, C)
Amethyst (Chevron or Banded)
Silicon Dioxide (SiO2) with iron impurities
Purple Agate (Dyed Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Dalmatian Jasper / Dalmatian Stone
Peralkaline Rock (Silicon Dioxide with Amphibole inclusions)
Quartzite
Quartzite (primarily SiO2)
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4
Sandstone (Ferruginous)
Arenite with Iron Oxide (Limonite/Hematite) coating
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Green Fluorite
Calcium Fluoride (CaF2)
Fluorite (Purple/Blue variety)
Calcium Fluoride (CaF2)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Staurolite (Cross Stone)
Staurolite (Fe2+2Al9Si4O23(OH))