Man Made Rock (Technosol)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Fossil Coral

Scleractinia (fossilized calcium carbonate)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

Emerald in Matrix

Beryl (Be3Al2Si6O18) containing Chromium/Vanadium impurities

Geode (unopened) or Calcareous Nodule

Siliceous or Calcareous Concretion/Nodule

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Basalt with Quartz/Feldspar Inclusions

Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining

Sandstone Beach Pebble

Clastic Sandstone (SiO2 - Quartz-dominant)

Rough Tanzanite

Zoisite (Ca2Al3(SiO4)3(OH))

Chert (Flint)

Chert (SiO2)

Amethyst

Silicon Dioxide (SiO2) with Iron impurities

Banded Chert or Agate

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Diabase

Diabase (also known as Dolerite)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Pink Opal

Amorphous Hydrous Silica (SiO2·nH2O)

Olivine/Peridot

Magnesium Iron Silicate (Mg,Fe)2SiO4

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)

Banded Chert (Agate-like Flint)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Amethyst (Rough)

Silicon Dioxide with iron impurities (SiO2)

Quartz Veined Siltstone or Graywacke

Clastic Sedimentary Rock with Quartz (SiO2) veining

Amygdaloidal Basalt with Agate/Chalcedony Infills

Amygdaloidal Basalt (Composition: SiO2 and (Mg,Fe)2SiO4 in matrix; SiO2 in amygdule)

Limestone Breccia

Sedimentary Breccia (Calcareous)

Chert / Jasper / Agate (Chalcedony Group)

Microcrystalline Quartz (SiO2)

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite or Quartz (SiO2/Silicates)

Yellow Ochre / Limonite

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Chert (and/or River Pebble)

Microcrystalline silica (SiO2)

Emerald In Matrix (Quartz/Calcite)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Specular Hematite

Specularite (Fe2O3)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Limonitic Iron Ore / Goethite

Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)

Granodiorite

Granodiorite (Intermediate to Felsic Intrusive Rock)

Pumice

Pumice (a highly vesicular volcanic glass)

Sandstone (likely Graywacke or Arkose variant)

Clastic Sedimentary Rock (SiO2 based)

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)

Porphyritic Basalt (primarily SiO2, Al2O3, FeO, MgO, CaO)

Basalt

Mafic volcanic rock, primarily composed of Plagioclase, Pyroxene, and Olivine

Basalt with Epidote Veining

Basalt (Mafic Extrusive Rock) with Ca2(Al,Fe)3(SiO4)3(OH)

Basalt with Vesicular Texture (Beach Cobble)

Vesicular Basalt (Aphanitic Igneous Rock)