Igneous Or Mineral

Tumbled white quartz pebble

Quartz, silicon dioxide (SiO₂), likely milky quartz

Quartz (Smoky/Clear variety)

Silicon Dioxide (SiO2)

Mixed Mineral Collection

Multi-mineral Assemblage (Quartz, Jasper, Obsidian, Pyrite, etc.)

Ruby (Raw Corundum)

Corundum (Al2O3) with Chromium traces

K-Feldspar (Potassium Feldspar)

Potassium Feldspar (KAlSi3O8)

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Gneiss (River Cobble)

Gneiss

Pegmatite or Graphic Granite

Intrusive Igneous Rock

Porphyry

Porphyritic Igneous Rock

Porphyry (Porphyritic Basalt / Andesite)

Porphyritic Igneous Rock

Granite Pebble

Intrusive Igneous Rock (Granite)

Diorite

Phaneritic Intermediate Igneous Rock

Bornite

Bornite (Cu5FeS4)

Obsidian

Volcanic Glass (SiO2 with impurities)

Uncertain small stone; possibly weathered quartz-bearing rock

Indeterminate from image; candidate materials include quartz-rich pebble or altered silicate rock

Dark weathered igneous rock, likely basalt

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Biotite (Black Mica)

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

Clear Quartz

Silicon Dioxide (SiO2)

Pyrite

Iron Disulfide (FeS2)

Fluorite (left), Sodalite (middle), Dumortierite/Tumbled Quartzite (right)

Calcium Fluoride (CaF2), Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2), Aluminum Borosilicate (Al7(BO3)(SiO4)3O3)

Quartz Geode

Silicon dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Granite

Felsic intrusive igneous rock

Milky Quartz

Silicon Dioxide (SiO2)

Epidote and Quartz in Basalt

Epidote [Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)] in Metabasalt

Magnetite or Hematite Nodule

Iron Oxide (Fe3O4 or Fe2O3)

Massive White Quartz

Silicon Dioxide (SiO2)

Magnetite / Lodestone

Magnetite (Fe3O4)

Green Aventurine

Aventurine Quartz (SiO2 + Fuchsite inclusions)

Sodalite

Na8(Al6Si6O24)Cl2

Magnetite / Hematite mix

Magnetite (Fe3O4) and Hematite (Fe2O3)

Blue Quartz

Silicon Dioxide (SiO2) with inclusions

Garnet

Pyrope or Almandine (X3Y2(SiO4)3)

Green Calcite

Calcium Carbonate (CaCO3)

Quartz Geode (with Calcite influence)

Silicon Dioxide (SiO2) with possible Calcium Carbonate (CaCO3)

Aventurine

Aventurine Quartz (SiO2)

Calcite

Calcium Carbonate (CaCO3)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Banded Agate

Agate (Silicon Dioxide - SiO2)

Hematite Ball

Iron(III) oxide (Fe2O3)

Granite

Intrusive Igneous Rock