Organic Gemstone (Not A Rock)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Carnelian (Red Chalcedony)

Silicon Dioxide (SiO2)

Common Opal with Host Rock

Opal (Hydrated silica, SiO2·nH2O)

Jasper (specifically Brecciated or Agated Jasper)

Silicon Dioxide (SiO2) - Chalcedony with impurities

Quartz Pebble

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Opal

Hydrated Silica (SiO2·nH2O)

Schist (Garnet-Mica Schist)

Garnet-Mica Schist

Dumortierite Quartz (Blue Quartz)

Al7BO3(SiO4)3O3 (Aluminum Boro-silicate included in Quartz)

Epidotite (Unakite variety)

Epidotized Granite (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Amethyst Quartz (Tumbled)

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Orange Quartzite (Tumbled Beach Pebble)

Quartzite (primarily SiO2)

Serpentine

Serpentinite (complex of Mg, Fe, Ni, Al, Zn, Mn)Si2O5(OH)4

Yellow Jasper (Iron-stained Quartz)

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Mookaite Jasper

Siliceous (chert) sedimentary rock, a form of Jasper

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Quartz (with iron oxide staining)

Silicon Dioxide (SiO2)

Obsidian

Obsidian (Volcanic Glass)

Quartz

Silicon dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2) / Rock Crystal

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper (likely Ocean Jasper or Variegated Jasper)

Silicon Dioxide (SiO2) with impurities

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Jasper (Green variety)

Silicon Dioxide (SiO₂)

Dalmatian Jasper (or Dalmatian Stone)

Dalmatian Stone (A peralkaline felsite composed of feldspar, quartz, and sodic amphibole)

Basalt with Peridotite Inclusion

Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith

Clear Quartz Cluster

Quartz (Silicon Dioxide - SiO2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Rough Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Dalmatian Jasper (Dalmatian Stone)

Dalmatian Stone (primarily Feldspar, Quartz, and Arfvedsonite/Tourmaline)

Ironstone Concretion / Limonite Node

Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)

Pyrite (on Quartz/Host Rock)

Iron Sulfide (FeS₂)

Obsidian

Obsidian (principally SiO2 + MgO, Fe3O4)

Agate

Silicon Dioxide (SiO2) - variety: Chalcedony

Peridotite (with Olivine and Pyroxene)

Ultramafic Magmatic Rock (Primary minerals: (Mg, Fe)2SiO4 and (Ca, Mg, Fe)2Si2O6)

Milky Quartz (with Iron Oxide staining)

Silicon Dioxide (SiO2)

Jasper

Silicon Dioxide (SiO2)