Black Obsidian
Volcanic Glass (SiO2)
Category
Browse mineral (native element alloy) specimens identified by the Rock Identifier community.
Black Obsidian
Volcanic Glass (SiO2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Agate with Druzy Quartz
Silicon Dioxide (SiO2)
Blue Diamond
Carbon (C) with trace Boron
Quartz on Matrix
Silicon Dioxide (SiO2)
Amber
Amber (C10H16O)
Yellow Quartz (Citrinated Quartz)
Silicon Dioxide (SiO2)
Cubic Zirconia (in Jewelry)
Zirconium Dioxide (ZrO2)
Onyx Marble (also commonly called Onyx)
Calcite (CaCO3), often with other mineral impurities
Tiger's Eye (Rough)
Macrocrystalline Quartz (SiO2 with inclusions of Crocidolite)
Quartz / Iron-Stained Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions/staining
Basalt River Stone
Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)
Gneiss
High-grade regional metamorphic rock (Foliated)
Basalt
Basalt (composition of plagioclase, pyroxene, and olivine)
Granite
Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica/Amphibole)
Sandstone (Ferruginous)
Arenite (with iron oxide cement)
Diorite
Diorite (Intermediate intrusive igneous rock)
Pyrite in Matrix (likely Quartz or Schist matrix)
Iron Sulfide (FeS2)
Celestite (Celestine)
Strontium sulfate (SrSO4)
Jasper (Green)
Silicon Dioxide (SiO2) with impurities
Pink Anthracite Coal (dyed)
Anthracite Coal (Artificially Colored)
Iron-stained Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Gneiss
Gneiss (High-grade Metamorphic Rock)
Rhodonite
Rhodonite (Mn2+SiO3)
Quartz (Druzy on Matrix)
Silicon Dioxide (SiO2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Granite (a felsic intrusive igneous rock)
Chrome Diopside
Magnesium Calcium Silicate (MgCaSi2O6) containing Chromium impurities
Yellow Jasper
Silicon Dioxide (SiO2) with Ferric Hydroxide impurities
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
Uraninite (Pitchblende)
Uranium dioxide (UO2)
Aventurine
Quartz (SiO2) with inclusions of Fuchsite
Green Aventurine
Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Quartz (Milky/Yellowish Pebble)
Silicon Dioxide (SiO2)
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Alkali Feldspar, and Plagioclase)
Serpentine, likely a variety of Chrysoprase (green chalcedony) or a similar translucent green mineral.
Serpentine Group Minerals (e.g., Antigorite, Lizardite) or Chalcedony (SiO2) with nickel impurities for Chrysoprase green.
Diamond (Lesedi La Rona specimen)
Diamond (Pure Carbon, C)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
Dendritic Agate (specifically Orange/Tumbled)
Silicon Dioxide (SiO2) with Oxide Inclusions