Industrial Byproduct (Anthropogenic Rock Like Material)

Ferruginous Sandstone (Gozzan)

Iron-rich clastic sedimentary rock with Limonite/Goethite

Quartzite Pebble

Quartzite (SiO2)

Quartz with Iron Staining

Silicon Dioxide (SiO2) with Ferruginous Oxides

Limestone

Calcite rock (CaCO3)

Chert (Field Stone)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Diorite (Salt and Pepper Rock)

Diorite

Petrified Wood

Silicified Wood (SiO2)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Diamond (in Jewelry Setting)

Carbon (C) - Isometric-Hexoctahedral

Diorite

Diorite (Intermediate intrusive igneous rock)

Rose Quartz

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

Chert (specifically Red Chert or Jasper)

Microcrystalline Quartz (SiO2)

Sandstone

Clastic sedimentary rock (primarily quartz arenite)

Rough Diamond

Diamond (pure Carbon, C)

Granitic Pegmatite Intrusion in Host Rock

Pegmatite dike in amphibolite or schist

Quartz Crystal Cluster

Quartz (Silicon Dioxide, SiO2)

Sandstone

Arenite (primarily Quartz, SiO2)

Black Obsidian

Volcanic Glass (predominantly SiO2, Silicon Dioxide)

Tumbled prehnite (probable)

Prehnite — Ca₂Al(AlSi₃O₁₀)(OH)₂

Chert Nodule

Microcrystalline Quartz (SiO2)

Calcite

Calcium Carbonate (CaCO3)

Garnetiferous Quartzite (Garnet Gneiss Pebble)

Garnet-bearing Quartzite or Quartz-Feldspar Gneiss

Chert (with Chalky Cortex)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Greenish translucent mineral fragment

Indeterminate; possibly serpentine, epidote, or green glassy feldspar

Diorite

Diorite (Intermediate intrusive igneous rock)

Quartzite Pebble

Quartzite (Silicon Dioxide: SiO2)

Granite Cobble

Granite (Phaneritic Igneous Rock)

Basalt (Road Aggregate Specimen)

Aphanitic mafic volcanic rock

Red jasper (iron-rich chalcedony), possibly brecciated

Jasper: microcrystalline quartz, SiO₂, colored mainly by iron oxides/hydroxides

Quartz

Quartz (SiO2 - Silicon Dioxide)

Banded Chert (or Flint)

Microcrystalline Quartz (SiO2)

Slate

Slate (Low-grade metamorphism of shale/mudstone)

White Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Coquina

Biogenic Limestone (mostly Calcium Carbonate, CaCO3)

Red Quartzite

Quartzite (SiO2 with iron oxide impurities)

Yellow Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Red Jasper

Jasper (a variety of Quartz, SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone (Tumbled / Rounded)

Sedimentary Rock (Quartz arenite)

Sandstone with Quartz Vein

Arenite with Crystalline Silica (SiO2)

Fuchsite

Chromium-bearing Muscovite - K(Al,Cr)2(AlSi3O10)(OH)2