Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Mineral
Category
Sedimentary Or Metamorphic (Low Grade)
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Quartz (likely Clear Quartz or Rock Crystal)
Quartz (SiO2)
Mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Mineral
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
mineral
Ruby
Corundum (Al2O3 with Chromium trace elements)
mineral
Heat-Treated Amethyst (Commercial Citrine)
Silicon Dioxide (SiO2) - Macro-crystalline Quartz
mineral
Chalcedony (Botryoidal or Agate nodule)
Silicon Dioxide (SiO2)
mineral
Mica (Biotite or Phlogopite variety)
Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
Mineral / Sedimentary occurrence
Green Tourmaline
Elbaite (part of Tourmaline group), Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4
mineral
Yellow Sapphire or Citrine
Al2O3 (Corundum) or SiO2 (Quartz)
mineral
Amber
(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.
Mineral
Banded Agate (specifically Chalcedony nodule)
Agate (Silicon Dioxide, SiO2)
mineral
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
mineral
Amethyst (Digital/Conceptual Representation)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
mineral
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide impurities
Mineral
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
mineraloid / anthropogenic (man-made origin)
Amethyst
Amethyst (SiO2 with Iron impurities)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Blue Lace Agate
Silicon dioxide (SiO2) - Chalcedony variety
mineral
Apache Tear
Obsidian (Hydrated Silica / Amorphous Volcanic Glass)
igneous
Malachite
Malachite (Cu2CO3(OH)2)
mineral
Feldspar (Orthoclase)
Orthoclase Feldspar (KAlSi3O8)
mineral
Mother of Pearl (Nacre)
Aragonite (CaCO3) with Organic Matrix
mineral
Orca Agate (Chalcedony)
Silicon Dioxide (SiO2) with inclusions
mineral
Labradorite (Larvikite variety)
Plagioclase Feldspar (Na,Ca)(Si,Al)4O8
igneous
Bull Quartz (Milky Quartz)
Quartz (Silicon Dioxide - SiO2)
mineral
Porphyritic Rhyolite (Red Porp)
Porphyritic Rhyolite (Felsic volcanic rock)
igneous
Quartz (Crystal Cluster)
Silicon Dioxide (SiO2)
mineral
Silver (Native Element)
Silver (Ag) in an alloy of 90% Silver and 10% Copper
mineral
Iron Meteorite (Campo del Cielo)
Iron Meteorite, Group IAB (FeNi Alloy: Kamacite and Taenite)
igneous
Amethyst
Amethyst (Silicon Dioxide - SiO2 with Iron impurities)
mineral
Carnelian
SiO2 (Silicon Dioxide) - Carnelian variety of Chalcedony
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Black Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Desert Rose
Gypsum (CaSO4·2H2O) or Barite (BaSO4) inclusions in sand
mineral
Bull Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Clear Quartz (Double Terminated)
Silicon Dioxide (SiO2)
mineral
Chrysocolla in Matrix
Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral