Quartz Druze on Matrix (Geode Fragment)
Quartz (Silicon Dioxide, SiO2)
Category
Browse the purple specimen is a mineral (amethyst); the white specimen is a sedimentary rock (limestone or marble). specimens identified by the Rock Identifier community.
Quartz Druze on Matrix (Geode Fragment)
Quartz (Silicon Dioxide, SiO2)
Druzy Quartz on Chalcedony Matrix
Silicon Dioxide (SiO2)
Cream Marble (Speckled)
Metamorphosed Limestone (mainly CaCO3)
Amethyst (Quartz variety)
Amethyst - SiO2 (Silicon Dioxide with Iron impurities)
Quartz
Silicon Dioxide (SiO₂)
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Quartz (likely Clear Quartz or Rock Crystal)
Quartz (SiO2)
Amethyst (Polished Cabochon)
Silicon Dioxide (SiO2) with iron impurities
Amethyst
Silicon Dioxide (SiO2) containing Iron impurities
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Lapis Lazuli (polished cabochon/sphere)
Na8[Al6Si6O24]Sn with accessory minerals (Pyrite, Calcite)
Amethyst
Amethyst (Varietal of Quartz), SiO2 (Silicon Dioxide)
Man-made Polished Porcelain Tile (Artificial Geologic Lookalike)
Fused Silicate Ceramic with Alumina (Synthetic Kaolinite derivative)
Heat-Treated Citrine (Amethyst-based)
Quartz (Silicon Dioxide) - SiO2
Lapis Lazuli
Lapis Lazuli (Primary mineral: Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz (Common or Milky Quartz)
Silicon Dioxide (SiO2)
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Amethyst
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Quartzite Pebble
Quartzite (SiO2 with minor impurities)
Quartz
Quartz (Silicon Dioxide - SiO2)
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
Orange Calcite (likely polished specimen)
Calcite
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe3+)
Marble
Recrystallized Calcite / Dolomite (CaCO3)
Amethyst (Quartz)
Amethyst (Silicon Dioxide with Iron impurities, SiO2)
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
White Marble
Calcite-rich Metasomatized Carbonate (CaCO3)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Calcite on Limestone (or Fossil)
Calcium Carbonate (CaCO3)
Quartz Druse (on Chalcedony/Agate base)
Silicon Dioxide (SiO2)
Marble
Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)
Calcite
Calcite (CaCO3)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Limestone with Calcite Veining
Calcium Carbonate (CaCO3)
Granite
Granite (High-silica plutonic rock)
Amethyst (Chevron or Banded variety)
Silicon Dioxide with Iron impurities (SiO2)
Limestone with Quartz or Calcite Veining
Calcium Carbonate (CaCO3) matrix with SiO2 or CaCO3 inclusions