Anthropogenic (Man Made Material Processed By Nature)

Red Sandstone

Arenite (SiO2 with Fe2O3)

Speckled rounded stone, likely granite or granitic gneiss

Granite/granitic gneiss; primarily quartz (SiO₂), feldspar, and dark mica or amphibole

Shale with Quartz Veins

Fissile Sedimentary Rock (SiO2)

Conical fossil shell or shell fragment

Likely a gastropod shell fragment; exact taxon indeterminate from the image

Sandstone (with Iron Staining)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Granite

Intrusive Igneous Rock

Granite

Intrusive Igneous Rock

Porphyritic Basalt

Porphyritic Basalt (with Plagioclase and Augite phenocrysts)

Turquoise

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

Rough turquoise-bearing rock (probable turquoise matrix)

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a host-rock matrix

Faceted blue gemstone, likely blue topaz or synthetic spinel

Topaz (Al₂SiO₄(F,OH)₂) or synthetic spinel (MgAl₂O₄); image insufficient for certainty

Bismuth Crystal

Bismuth (Bi)

Sandstone

Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)

Yellow chalcedony (likely heat-treated or resin-coated)

Microcrystalline quartz, SiO₂

Sandstone (likely Quartzose)

Arenite (primarily SiO2)

Sandstone Pebble (River Rock)

Sandstone (Quartz-rich sedimentary rock with iron oxide staining)

Red jasper pebble

Jasper, microcrystalline quartz (SiO₂) colored mainly by iron oxides

Red jasper-like chalcedony pebble

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper

Weathered granite (feldspathic, iron-stained granite)

Granite; primarily quartz, potassium feldspar, plagioclase feldspar, and minor mica/amphibole. Exact identification is uncertain from a single photograph.

Gold-bearing Quartz Vein in Mafic Rock

Hydrothermal Quartz Vein within Greenschist/Amphibolite facies (SiO2 with Au)

Red Jasper or Chert

Jasper (SiO2, a variety of chalcedony with iron oxide impurities), Chert (SiO2)

Granite

Intrusive Igneous Rock

Granite

Intrusive Igneous Rock

Granite

Granite (Phaneritic Igneous Rock)

Granite

Intrusive Felsic Igneous Rock

Digital Multimeter (Synthetic Object)

Digital Multimeter (DMM)

Quartz vein rock with iron-stained matrix

Quartz (SiO₂), likely with limonite/goethite and minor feldspar or mica

Dark gray basalt or andesite cobble

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase feldspar, pyroxene, and possibly olivine

Citrine Quartz

Citrine (Silicon Dioxide - SiO2)

Fossil gastropod shell

Fossilized marine gastropod; exact genus/species requires locality and examination

Jasper

Microcrystalline Quartz (SiO2)

Red Coral

Corallium rubrum (for precious red coral), although other species like Corallium japonicum and Paracorallium are also used.

Red synthetic corundum (ruby-colored lab-grown sapphire)

Corundum, aluminum oxide (Al₂O₃), likely synthetic and chromium-colored

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Citrine

Silicon Dioxide (SiO2)

Metallic sulfide ore, likely pyrite-bearing rock

Pyrite (FeS₂), possibly with chalcopyrite and quartz/host rock

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)

Clear quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Granite

Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)

Red jasper (iron-rich chalcedony), possibly brecciated

Jasper: microcrystalline quartz, SiO₂, colored mainly by iron oxides/hydroxides

Shale (sub-type: Carbonaceous Shale)

Lutaceous Sedimentary Rock