Mineral Precipitate (Anthropogenic Context)

Jasper

Silicon dioxide (Microcrystalline Quartz, SiO2)

Amazonite

Potassium Aluminum Silicate (KAlSi3O8)

Chalcedony (Agate Pebble)

Silicon Dioxide (SiO2)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Prehnite

Prehnite, Ca2Al2Si3O10(OH)2

Smoky Quartz with Feldspar

SiO2 (Quartz) with KAlSi3O8 (Potassium Feldspar)

Tiger's Eye

Fibrous Quartz (SiO2) with iron inclusions

Azurite-Malachite (often a mixed specimen)

Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2(CO3)(OH)2. The specimen appears to be a natural mixture or intergrowth of these two minerals.

Dream Amethyst (Chevron Amethyst)

Silicon Dioxide with Iron impurities (SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz in Host Rock

Silicon Dioxide (SiO2) in Rhyolite or Granite matrix

Diorite

Diorite (Intermediate intrusive igneous rock)

Fossilized Shark Tooth (Basal Bone)

Otodus sp. (Mineralized Hydroxyapatite)

Quartzite with Glauconitic or Iron staining

Quartzite (SiO2 with accessory minerals)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Magnetite

Magnetite (Fe3O4)

Pyrite

Iron Sulfide (FeS2)

Sandstone

Arenite (Siliclastic sedimentary rock)

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Blue Apatite

Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)

Granite fragment

Granite (Felsic Plutonic Rock)

Green Chalcedony

Silicon Dioxide (SiO2) with trace minerals

Included Quartz Beads (likely Phantom Quartz or Garden Quartz)

Quartz (SiO2) with various mineral inclusions

Bicolor Quartz Pebble

Silicon Dioxide (SiO2) with mineral inclusions

Glauconite (Glauconitic Sandstone)

Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]

Howlite

Howlite (Ca2B5SiO9(OH)5)

Granite

Granite (composed mainly of Quartz, Feldspar, and Mica)

Schist

Mica Schist

Rhodochrosite

Manganese Carbonate (MnCO3)

Sandstone

Clastic Sedimentary Rock (composed mostly of SiO2)

Sandstone (likely Arkosic or Quartzose)

Arenite (SiO2 based with mineral inclusions)

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 principal composition)

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Peacock Ore

Bornite (Cu5FeS4)

Jade (likely Nephrite Jade based on appearance)

Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)

Turquoise

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

Ironstone Concretion (Limonite/Goethite)

Ironstone (primarily FeO(OH)·nH2O)

Basalt with Calcite Veins

Aphanitic mafic volcanic rock with CaCO3 inclusions