Igneous Rock

Snowflake Obsidian

Vitreous Volcanic Rock (Amorphous Silicate), SiO2

Demitasse Granite (Diorite-Granite transition)

Intermediate Plutonic Rock (Granodiorite/Diorite mix)

Basalt

Mafic Volcanic Rock (Primarily Plagioclase and Pyroxene)

Granite

Granite (Felsic Plutonic Rock / SiO2 + Al2O3)

Gold Ore

Auriferous Quartz and Sulfide Mineralization in Host Rock

Granite

Granite (Phaneritic Quartz-Feldspar intrusive rock)

River Pebble (Gabbro or Dark Sandstone variety)

Mafic Intrusive Rock (Plagioclase Feldspar and Pyroxene)

Pink Granite

Phaneritic plutonic rock (dominated by Alkali Feldspar)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Calcite (Yellow/Orange variety - sometimes called Honey Calcite)

Calcite

Granodiorite (Gneissic Pebble)

Granodiorite displaying minor foliation

Tree Agate

Dendritic Agate (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Pink Granite

Phaneritic Plutonic Felsic Rock (K-feldspar rich)

Pink Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky or Cloudy Quartz)

Silicon Dioxide (SiO2)

Gold Nugget

Native Gold (Au)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)

Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)

Mica Schist (with Golden/Biotite inclusions)

K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)

Peridot in Basalt/Xenolith

Olivine (Mg, Fe)2SiO4 in Vesicular Basalt

Graphic Granite (Zebra Rock)

Pegmatitic Granite (composed of Quartz and K-Feldspar)

Chevron Amethyst

Silicon Dioxide (SiO2) with iron impurities

Gneiss

Gneiss

Agate (specifically Carnelian or Honey Agate)

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Quartz

Quartz (SiO₂)

Quartz (Milky/Vein Quartz)

Silicon Dioxide (SiO2)

Rose Quartz

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

Smoky Quartz (with possible Feldspar inclusions)

Silicon Dioxide (SiO2)

Mica (Biotite or Phlogopite variety)

Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky or Clear Quartz fragment)

Silicon Dioxide (SiO2)

Porphyritic Basalt or Diabase with Plagioclase Phenocrysts

Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar

Greenschist with Quartz Veining

Greenschist (commonly containing Chlorite, Actinolite, and Epidote)

Thunderegg (Ate Agate/Jasper Geode)

Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Serpentine with Quartz Vein

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4 with SiO2 veins

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Gneiss (Schistose)

Gneiss

Pumice

Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)