Mineral, Specifically A Rock Fragment

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock including secondary mineral infills)

Diorite

Phaneritic intermediate plutonic rock

Note on Image Identification: Textile

N/A (Anthropogenic material)

Granite Cobble

Granite (Phaneritic Igneous Rock)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Granodiorite

Granodiorite (intermediate plutonic rock)

Gneiss

Gneiss (a type of metamorphic rock)

Olivine in Basalt (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4 (Mineral) within Basalt (Rock)

Basalt with Hematite staining

Extrusive mafic igneous rock with Fe2O3

Sandstone

Arenite (SiO2 principal component)

Plume Agate

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Basalt

Basalt (extrusive igneous rock)

Quartz Geode (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Basalt

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Vesicular Basalt with Amygdaloidal Infill

Basalt (Mafic Extrusive Igneous Rock)

Cobalt Glass Slug (Cullet)

Man-made Silicate Glass with Cobalt Oxide (CoO)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Amygdaloidal Basalt with Zeolite/Quartz Infill

Amygdaloidal Basalt (Host: (Mg,Fe)2SiO4 / CaAl2Si2O8; Infill: SiO2 or Na2Al2Si3O10·2H2O)

Chert / Flint

Cryptocrystalline quartz (SiO2)

Geode (Unopened)

Silicon Dioxide (SiO2) in sedimentary vugs

Bauxite

Bauxite (Al(OH)3, AlO(OH))

Milky Quartz Pebble (Iron-Stained)

Silicon Dioxide (SiO2)

River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)

Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)

Quartz pebble with surface markings

Silicon Dioxide (SiO2)

Chalcedony (Common Agate)

Silicon Dioxide (SiO2)

Quartz / Common Agate

Silicon Dioxide (SiO2)

Turquoise

Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Dalmatian Stone

Dalmatian Jasper (a misnomer for an Aplite with Arfvedsonite spots)

Banded Agate

Cryptocrystalline variety of Quartz (SiO2)

Quartz Pebble (Water-worn Quartzite)

Silicon Dioxide (SiO2)

Bauxite

Bauxite (mixture of Hydrous Aluminum Oxides)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Lapis Lazuli

Lazurite-dominant Metamorphic Rock (complex aluminosilicate)

Agatized Petrified Wood

Silicon Dioxide (SiO2) - Chalcedony pseudomorph after Wood

Basalt with Quartz/Feldspar Inclusions

Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining

Amygdaloidal Basalt with Agate/Chalcedony Infills

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

Shale

Shale (Sedimentary rock composed of mud/clay minerals)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Quartz Geode

Silicon Dioxide (SiO2)