Sedimentary (Secondary Mineral) Within Igneous

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Earthy Hematite / Goethite Surface

Iron Oxide (Fe2O3 – α-FeO(OH))

Prehnite

Calcium aluminum silicate hydroxide - Ca2Al(AlSi3O10)(OH)2

Malachite

Malachite - Cu2CO3(OH)2

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Gold Nugget

Native Gold (Au)

Chrysocolla on Matrix

Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·nH2O

Specular Hematite (Specularite) in Matrix

Specularite (Fe2O3)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Chrysocolla

Chrysocolla, (Cu, Al)2H2Si2O5(OH)4·nH2O

Carnelian Agate Nodule

Chalcedony (SiO2) with Iron Oxide inclusions

Agate in Rhyolite

Silicon Dioxide (Quartz/Chalcedony) in Volcanic Rock matrix

Pink Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Schist

Mica Schist (formula variable based on mineral content, typically containing [K,Al,Fe,Mg,Si,O,H])

Covellite

Covellite (CuS)

Limonite with Quartz

FeO(OH)·nH2O (Limonite) with SiO2 (Quartz)

Limonite/Goethite Nodule

Iron Oxyhydroxide (primarily FeO(OH)·nH2O)

Chrysocolla on Quartz with Iron Oxides

Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)

Hemimorphite on Limonite Gossan

Hemimorphite (Zn4Si2O7(OH)2·H2O) on Limonite matrix

Ferruginous Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions (Limonite/Goethite)

Tree Agate

Silicon dioxide (SiO2)

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)

Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.

Milky Quartz

Silicon Dioxide (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with Iron Oxides

Amethyst Geode Fragment

Amethyst (Silicon Dioxide, SiO2) with Quartz matrix

Quartz Geode

Crystalline Silicon Dioxide (SiO2)

Calcite Geode

Calcium Carbonate (CaCO3)

Diamond

Diamond (pure carbon; C)

Granite

Granite (Felsic Plutonic Rock)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite with Quartz Veining

Quartzite (primarily SiO2)

Dalmatian Stone

Dalmatian Jasper (Aphanitic Igneous Rock with Arfvedsonite inclusions)

Mahogany Obsidian

Volcanic glass (Silicon Dioxide with Hematite/Magnetite inclusions)

Red Rhyolite Porphyry

Rhyolite (Porphyritic texture)

Tumbled labradorite

Labradorite, a calcium-rich plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

Chert (Iron-stained)

Silicon Dioxide (SiO2) with Ferruginous impurities

Granite

Granitoid (comprised of Quartz, Feldspar, and Mica)

Herkimer Diamond

Quartz (Silica - SiO2)

Vanadinite

Lead Chlorovanadate, Pb5(VO4)3Cl

Quartz

Silicon dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)