Metamorphic (Altered Igneous Rock)

Polished Ocean Jasper (likely)

Silicified orbicular rhyolite; primarily microcrystalline quartz (SiO₂)

Quartz-rich metamorphic pebble, possibly jade-like greenstone

Likely quartzite or altered basalt/greenstone; visible minerals may include quartz, feldspar, chlorite/epidote, and iron oxides

Weathered iron-rich volcanic rock (probable basalt/andesite)

Altered basaltic to andesitic volcanic rock; composition likely plagioclase, pyroxene, and iron oxides

Biotite (Black Mica)

Biotite - K(Mg,Fe)3(AlSi3O10)(F,OH)2

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Rounded gray-green stone, likely serpentinite

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite

Clear Quartz (Faceted)

Silicon Dioxide (SiO2)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Garnet (Almandine/Pyrope series)

Garnet Group - X3Y2(SiO4)3

Tumbled sandstone or quartz-rich sedimentary pebble

Likely quartz–feldspar sandstone (SiO₂-rich clastic rock); exact identification requires testing

Rounded pale-green pebble, likely serpentinite or altered basalt

Probable serpentinite (serpentine-group minerals) or weathered mafic rock; exact identification requires testing

Tumbled copper-bearing rock, likely chrysocolla-bearing basalt or copper ore

Chrysocolla (hydrated copper phyllosilicate, approximately Cu₂H₂Si₂O₅(OH)₄·nH₂O) in a dark volcanic host

Rounded white pebble, likely quartz or feldspar

Most consistent with milky quartz (SiO₂), though altered feldspar or calcite is possible from the image

Gneiss

Metamorphic Gneiss

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with Iron inclusions)

Quartz (Orange/Pink variety)

Silicon Dioxide (SiO2)

Tumbled Quartz

Silicon Dioxide (SiO2)

Foliated Gneiss

Gneiss (Metamorphic Rock)

Gneiss

Gneissic Metamorphic Rock

Orange calcite

Calcite (CaCO₃), likely a botryoidal or rough aggregate

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Weathered quartz-rich stone (likely chert or quartzite)

Quartzite or microcrystalline quartz (SiO₂); exact identification is uncertain from the image

Turquoise

Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Clear Quartz (Rock Crystal) Bracelet

Silicon Dioxide (SiO2)

Ruby in Fuchsite (often sold as Ruby in Zoisite)

Corundum (Al2O3) in Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Copper-bearing rock, likely bornite/chalcopyrite ore in quartz matrix

Bornite (Cu₅FeS₄) and/or chalcopyrite (CuFeS₂), with quartz (SiO₂) and dark gangue minerals

Garnet-bearing metamorphic rock, possibly garnet amphibolite or mica schist

Almandine garnet (Fe₃Al₂Si₃O₁₂) in a mafic, amphibole–feldspar-rich matrix

Quartz-bearing ironstone or breccia

Silicified iron-rich breccia; mainly quartz (SiO₂), iron oxides/hydroxides, and altered host rock

Schist

Metamorphic Rock (Schist)

Banded Gneiss

Gneiss (Metamorphic Rock)

Milky Quartz

Silicon Dioxide (SiO2)

Greenish Metamorphic Rock (likely containing epidote or chlorite)

Metamorphic rock, possibly epidosite or greenstone

Quartz Pebble

Silicon Dioxide (SiO2)

Banded Gneiss

Gneiss (Metamorphic Rock)

Basalt Pebble

Extrusive Igneous Rock

Quartz with Iron Staining

Silicon Dioxide (SiO2)

Greenish Feldspathic Rock / Epidote Granite (Unakite-type or Epidote-bearing rock)

Epidotized Metamorphic/Igneous Rock

Unakite

Altered Granite (Orthoclase Feldspar, Epidote, and Quartz)

Raw greenish-blue quartz-bearing mineral specimen

Likely fluorite or chalcedony/quartz; exact identification requires hardness and crystal tests

Chert Nodule in Limestone

Sedimentary rock comprising microcrystalline quartz (chert) and calcium carbonate (limestone)