Sedimentary Or Igneous (Secondary Formation)

Chert with Quartz/Calcite Vein

Microcrystalline Silica (SiO2)

Geode (unopened)

Calcedony-lined Geode (SiO2)

Basalt with Epidote (Flowerstone-like texture)

Amygdaloidal Basalt (silicate mineral inclusions)

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Granite

Granite (Mainly Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)

Bumble Bee Jasper

Volcanic Tuff (mixture of SiO2, CaCo3, S, and As2S3)

Granite

Phaneritic Felsic Igneous Rock (primarily Quartz, Alkali Feldspar, and Plagioclase)

Carnelian Agate

Silicon Dioxide (SiO2) with Ferric Oxide inclusions

Amethyst

Amethyst (Varietal of Quartz), SiO2 (Silicon Dioxide)

Aventurine

Aventurine Quartz (SiO2 with inclusions)

Gneiss

Gneissic Metamorphic Rock (Mineral composition: Quartz, Feldspar, Amphibole/Biotite)

Granitoid (Granitic Rock)

Granitoid (Quartzo-feldspathic plutonic rock)

Granite

Granite

Malachite

Malachite (Cu2(CO3)(OH)2 - a copper carbonate hydroxide mineral)

White Quartz

Quartz (SiO2)

Granodiorite Pebble

Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite/Amphibole)

Granite (Weathered)

Grano-diorite / Granite (SiO2 rich intrusive rock)

Pyrite

Iron Disulfide (FeS2)

River Cobble (Salt and Pepper Gneiss)

Gneiss (High-grade regional metamorphic rock)

Basalt with Iron Oxidation

Mafic Igneous Basalt

Gneiss (Granitic Gneiss)

Gneiss (from German Gneis, related to 'spark')

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Rhodochrosite

Manganese Carbonate (MnCO3)

Red Jasper (Polished)

Silicon Dioxide (SiO2) with Hematite inclusions

Turquoise (Rough)

Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Orange Calcite

Calcium Carbonate (CaCO3)

Quartz Pebble (likely Chalcedony or Quartzite)

Silicon Dioxide (SiO2)

Psilomelane (Manganese Ore)

Psilomelane (Ba,H2O)2Mn5O10

Limonite with Iron Inclusions

Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)

Biotite Mica

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

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Dyed Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Boxwork Quartz / Septarian Jasper

Boxwork (SiO2 with iron oxide inclusions)

Basalt

Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)

Granite Cobble

Granite (Felsic Intrusive)

Vesicular Basalt with Secondary Mineral Infill

Mafic Volcanic Rock (Basalt)

Banded Gneiss

Gneiss (quartz-feldspar-biotite metamorphic rock)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Satin Spar (Gypsum)

Calcium Sulfate Dihydrate (CaSO4·2H2O)