Mineral Precipitate (Anthropogenic Context)

Glauconitic Sandstone

Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Epidote in Basalt

Epidotized Basalt (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH) in Mafic Igneous Host)

Olivine in Basalt matrix

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Turquenite (Dyed Howlite)

Dyed Ca2B5SiO9(OH)5 (Calcium Borosilicate Hydroxide)

Orbicular Jasper (Ocean Jasper variant)

Silicon Dioxide (SiO2) with iron oxide inclusions

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Lepidolite on Pegmatite

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

Tiger's Eye (Brown/Dark variety)

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Sandstone (Greywacke/Siltstone variant)

Arenite / Wacke (SiO2 with diverse mineral inclusions)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Sandstone

Arenite

Jasper

Jasper (Silicate mineral, SiO2)

Jasper

Jasper (Silicate mineral, SiO2)

Aragonite

Aragonite (Carbonate mineral), CaCO3

Pearl

Organic Mineral (CaCO3 with conchiolin)

Chert (Jasper variation)

Chert (Silicate mineral, SiO2)

Quartzite

Quartzite (Primary mineral: SiO2)

Banded Gneiss

Gneiss (variable mineral composition)

Sandstone (likely Quartzose)

Arenite (SiO2 principal mineral)

Amethyst

Amethyst (Silica mineral, SiO2)

Sandstone

Sandstone (various mineral compositions)

Amygdaloidal Basalt

Basalt with secondary mineral infilling

Red Jasper

Jasper (Silicate Mineral - SiO2)

Schist

Mica Schist

Chalcedony Nodule (Commonly known as Agate or Chert)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (primarily SiO2)

Granitic Pegmatite

Granitic Pegmatite (principally Quartz, Potassium Feldspar, and Mica)

Green Calcite

Calcite (CaCO3)

Banded Agate (specifically Sardonyx or Red Agate)

Silicon Dioxide (SiO2)

Chevron Amethyst

Silicon Dioxide (SiO2) with trace Iron (Fe3+)

Sandstone (likely Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Satin Spar (Gypsum)

Hydrous Calcium Sulfate (CaSO4·2H2O)

Quartz Pebble (with Mica or Iron staining)

Silicon Dioxide (SiO2)

Turquoise (possible Dyed Howlite or Magnesite imitation)

CuAl6(PO4)4(OH)8·4H2O (Turquoise)

Ferruginous Quartz (Iron-Stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Azurite with Malachite and Limonite

Azurite Cu3(CO3)2(OH)2 / Malachite Cu2CO3(OH)2

Turquoise

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