Industrial Byproduct

Mica Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Schist

Mica Schist

Rose Quartz and Milky Quartz

Silicon Dioxide (SiO2)

Anthracite Coal

Anthracite

Chert (specifically Blue Chert/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Diamond

Diamond (C)

Black Tourmaline

Schorl (Sodium iron aluminum borosilicate), NaFe3Al6(BO3)3Si6O18(OH)4

Chalcedony (Agate/Carnelian variety)

Cryptocrystalline Quartz (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Blue Kyanite

Kyanite (Al2SiO5)

Satin Spar (Selenite Gypsum Sphere)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Chalcedony

Chalcedony (SiO2)

Granite (Core Sample)

Phaneritic Felsic Igneous Rock (Granite)

Chert (often called Flint when dark or worked)

Cryptocrystalline silica (SiO2)

Garnet

Garnet group [X3Y2(SiO4)3]

Green Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide - SiO2)

Garnet-Bearing Schist

Almandine Garnet Micaceous Schist

Tumbled Clear Quartz and Citrine Points

Silicon Dioxide (SiO2)

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

Grey Chalcedony (Tumbled Moon)

Microcrystalline Quartz (SiO2)

Rough Corundum (likely Sapphire/Zircon-bearing)

Aluminium Oxide (Al2O3)

Banded Agate

Agate (Microcrystalline Chalcedony/Quartz, SiO2)

Orange Calcite

Calcium Carbonate (CaCO3) with Iron Oxide inclusions

Chert (specifically tan/pink variety)

Silicon Dioxide (SiO2)

Red Garnet (Pyrope or Almandine)

Magnesium aluminum silicate (Mg3Al2(SiO4)3) or Iron aluminum silicate (Fe3Al2(SiO4)3)

Honey Calcite

Calcium Carbonate (CaCO3)

Barite Rose on Marcasite

Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)

Blue Calcite

Calcium Carbonate (CaCO3)

Garnet (specifically Almandine or Pyrope)

Almandine: Fe3Al2(SiO4)3 or Pyrope: Mg3Al2(SiO4)3

Quartz Druzy on Matrix (likely Agate or Jasper)

Silicon Dioxide (SiO2) with various mineral inclusions

Satin Spar (Selenite)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Milky Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

Orange Quartzite / River Pebble

Silicon Dioxide (SiO2) - Recrystallized Sandstone

Milky Quartz

Quartz (SiO2) with iron staining

Epidote in Matrix

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Jasper and Quartz River Pebble

Silicon Dioxide (SiO2) with impurities

Chert (specifically Flint or Dark Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Black Sapphire

Corundum (Al2O3 with inclusions of hematite or ilmenite)

Garnet

Garnet Group (Silicate mineral); general formula X3Y2(SiO4)3

Satin Spar (often marketed as Selenite)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Rose Quartz

SiO2 (Silicon Dioxide)