Fossilized Brachiopod
Phylum Brachiopoda (replaced by Calcite/CaCO3)
Category
Browse organic (if resin) or synthetic (if glass); simulating sedimentary or metamorphic (for natural stones) specimens identified by the Rock Identifier community.
Fossilized Brachiopod
Phylum Brachiopoda (replaced by Calcite/CaCO3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
Dolomite or Limestone (Carbonate Rock)
CaMg(CO3)2 (Dolomite) or CaCO3 (Limestone / Calcite)
Lapis Lazuli
Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Jasper (Wonderstone/Banded Jasper)
Silicon Dioxide (SiO2) with iron oxide impurities
Quartz Pebble
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Basalt (River Pebble)
Basalt
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) in matrix
Orange Calcite
Calcium Carbonate (CaCO3)
Granite (Pegmatitic)
Phaneritic Felsic Igneous Rock
Rose Quartz
Silicon Dioxide (SiO2)
Chert (Flint variety)
Chert (SiO2)
Diamond
Diamond (C)
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Rugose Coral (Horn Coral Fossil)
Order Rugosa (fossilized in limestone/chert)
Green Glass (often marketed as 'Obsidian' or 'Green Quartz')
Amorphous Silica (SiO2) with copper or chromium additives
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron
Fossilized Coral (Petoskey Stone / Favosites)
Favosites (extinct genus of tabulate coral)
River Pebble (Gneiss or Quartzite variant)
Course-grained Metamorphic Rock (likely SiO2 dominant)
Eclogite
Eclogite (Omphacite-Garnet rock)
Jasper and Quartz River Pebble
Silicon Dioxide (SiO2) with impurities
Garnet (Almandine variety)
Almandine Garnet (Fe3Al2(SiO4)3)
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
Basalt with Quartz/Calcite Vein
Amygdaloidal Basalt (matrix) with Mineral Vein filling
Siltstone
Siltstone (composed of microscopic silt-sized particles of quartz and feldspar)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Banded Siltstone or Argillite
Siltstone (primarily SiO2 with Al and Fe oxides)
Kyawthuite
Kyawthuite (Bi3+Sb5+O4)
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geodic structure
Basalt (Greenstone/Trap Rock)
Basalt (dominated by plagioclase feldspar and pyroxene)
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 based)
Hematite
Ferric oxide (Fe2O3)
Tiger's Eye
Tiger's Eye (Pseudomorph of Quartz after Crocidolite), SiO2
Chalcedony (Common Opal or Agate variant)
Silicon Dioxide (SiO₂)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Conglomerate
Conglomerate (clastic sedimentary rock)
Chert / Flint Nodules in Limestone
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Glauconitic Sandstone
Glauconitic Sandstone (complex silicate formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Quartz
Quartz (SiO₂ - Silicon Dioxide)