Mineral Based Composite

Sandstone

Arenite (primarily SiO2)

Sandstone Beach Pebble

Clastic sedimentary rock (SiO2 with iron oxide cement)

Tourmalinated Quartz

Quartz (SiO2) with included Tourmaline (complex borosilicate)

Moss Agate

Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)

Sandstone

Arenite (SiO2 based typically)

Asphalt Concrete (Bituminous Conglomerate)

Anthropogenic Bituminous Conglomerate

Diamond (Princess Cut Faceted Gemstone)

Native Carbon (C)

Rose Quartz

Quartz (Silicon Dioxide - SiO2) with trace amounts of titanium, iron, or manganese

Chrysocolla in Matrix

Hydrated copper silicate - (Cu,Al)2H2Si2O5(OH)4·nH2O

Banded Calcite (often sold as 'Green Onyx')

Calcite (Calcium Carbonate, CaCO3)

Lapis Lazuli

Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)

Amazonite

Amazonite (KAlSi3O8)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Blue Kyanite

Kyanite (Al2SiO5)

Charoite

Charoite (K(Ca,Na)2Si4O10(OH,F)·H2O)

Red Sandstone (Iron-Rich)

Arenite (Fe2O3)

Rough Diamond

Diamond (pure Carbon, C)

Limonite (Bog Iron)

Limonite (Hydrated iron(III) oxide-hydroxide) - FeO(OH)·nH2O

Shale (with Iron Oxide staining)

Fissile Mudstone (primarily Quartz and Clay minerals)

White Quartz Sphere

Silicon Dioxide (SiO2)

Unknown Organic Object (likely a berry or fruit)

Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Sandstone

Arenite (primarily SiO2)

Aquamarine

Beryl (Be3Al2Si6O18 with iron impurities)

Quartz pebble

Silicon Dioxide (SiO2)

Smoky Quartz Cluster

Smoky Quartz (Silicon Dioxide - SiO2)

Epidote

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

Sandstone

Arenite (primarily SiO2)

Tiger Iron

Tiger Iron (composite of Tiger's Eye, Red Jasper, and Hematite)

Fluorite (Green Fluorite on Host Rock)

Fluorite (Calcium Fluoride, CaF2)

Green Fluorite

Calcium Fluoride (CaF2)

Green Calcite

Calcium Carbonate (CaCO3)

Gold

Gold (Native Element); Au

Sandstone (Red)

Arenite (primarily Quartz, SiO2, with Iron Oxide cement)

Gneiss

Gneiss (High-grade metamorphic rock)

Red Sandstone

Arenite (predominantly Quartz with Hematite cementation)

Diorite

Diorite (Intermediate intrusive igneous rock)

Sandstone Clast

Arenite (primarily SiO2)

Chrysocolla in Matrix

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

Sedimentary Breccia

Clastic Breccia (CaCO3/SiO2 matrix)

Black Tourmaline (Schorl)

Schorl (Sodium iron silicate hydroxide boron silicate); NaFe3Al6(BO3)3Si6O18(OH)4

Gold

Native Gold (Au)