Igneous Rock

Quartzite (river pebble) and Gabbro (crushed rock)

Quartzite (metamorphosed Quartz Sandstone, SiO2) and Gabbro (Plagioclase-Clinopyroxene rock)

Dalmatian Jasper (Dalmatian Stone)

Peralkaline rhyolite

Obsidian

Volcanic Glass (SiO2)

Smoky Quartz and Chalcedony Geode Fragment

Silicon Dioxide (SiO2)

Obsidian

Obsidian (Volcanic Glass)

Larvikite

Monzonite (intermediate intrusive igneous rock containing plagioclase, alkali feldspar, and minor dark minerals)

Granite

Granite (a phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)

White Topaz

Topaz [Al2SiO4(F,OH)2]

Dragon Blood Jasper

Epidote-containing Quartz Chalcedony (SiO2 with Ca2(Al, Fe)3(SiO4)3(OH))

Dragon Vein Agate

Chalcedony (Quartz) - SiO2

Jasper

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Basalt

Basalt (comprising plagioclase, pyroxene, and olivine)

Agate

Silicon Dioxide (SiO2) - Chalcedony variety

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Granite

Phaneritic intrusive igneous rock (composed mainly of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Mica)

Red Quartz (Carnelian/Red Jasper Agate)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Basalt (River Rock/Cobble)

Basalt (no specific mineral formula as it's a rock)

Obsidian

Obsidian (Volcanic Glass, complex silicate)

Obsidian

Obsidian (principally SiO2)

Dalmatian Jasper (or Dalmatian Stone)

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

Granite Cobble / Rounded Granite River Rock

Granite

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Flower Agate

Chalcedony (Silicon Dioxide) with Plume Inclusions, SiO2

Obsidian

Obsidian (principally SiO2)

Basalt (Vesicular)

Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene

Black Obsidian

Volcanic Glass (predominantly SiO2, Silicon Dioxide)

Nuummite

Nuummite (Orthoamphibole rock composed of Anthophyllite and Gedrite)

Obsidian

Obsidian (Volcanic Glass, primarily SiO2)

Basalt Pebble

Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)Si2O6 and (Ca, Na)AlSi3O8

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Granite Cobble

Felsic intrusive igneous rock (composition: SiO₂ with KAlSi₃O₈, NaAlSi₃O₈, and CaAl₂Si₂O₈)

Granite with Biotite and Quartz

Phaneritic Felsic Igneous Rock (composed of SiO2, KAlSi3O8, and K(Mg,Fe)3AlSi3O10(OH)2)

Granite

Granite

River Rock (Basalt)

Basalt (SiO2 range: 45-52%)

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2) with various iron-oxide inclusions

Unakite (often traded as Dragon Blood Jasper)

Epidotized Granite

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2, with varying amounts of Calcite, Pyrite, and Sodalite).

Granite

Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)

Granite

Granite (phaneritic intrusive igneous rock consisting of 20-60% quartz, orthoclase/plagioclase feldspar, and mica/amphibole)

Granite (with Muscovite Mica)

Phaneritic Felsic Igneous Rock (primarily Quartz SiO2, K-Feldspar KAlSi3O8, and Muscovite KAl2(AlSi3O10)(OH)2)

Black Obsidian

Obsidian, SiO2 (amorphous)

Obsidian

Obsidian (volcanic glass)