Man Made Material

Quartz

Quartz (SiO2 - Silicon Dioxide)

Granite

Phaneritic Igneous Rock (Granite)

Muscovite mica

Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Serpentinite (likely)

Serpentinite, dominated by serpentine-group minerals (antigorite, lizardite, or chrysotile)

Sandstone

Arenite (primarily SiO2 with trace Fe2O3)

Chert (Jasper/Flint variety)

Silicon dioxide (SiO2)

Limestone (Grey and White specimens)

Calcium Carbonate (CaCO3)

Iron-rich sandstone or lateritic rock

Ferruginous sandstone; predominantly quartz (SiO₂) cemented or stained by iron oxides/hydroxides

Weathered fossiliferous limestone fragment, possibly fossil coral or shell material

Indeterminate carbonate fossil in calcitic limestone; likely composed mainly of calcite (CaCO₃), but species identification is not possible from this image alone

Sandstone

Clastic Sedimentary Rock

Serpentinite with carbonate veins

Serpentinite; chiefly serpentine-group minerals (antigorite/lizardite, Mg₃Si₂O₅(OH)₄) with white calcite or magnesite veins

Weathered greenstone (likely serpentinite or altered basalt)

Serpentinite-group rock, commonly dominated by serpentine minerals (antigorite/lizardite); exact identification requires testing

Snowflake Obsidian

Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)

Peacock ore (iridescent chalcopyrite, possibly bornite)

Chalcopyrite, CuFeS₂; the iridescent surface may be natural tarnish or artificial acid treatment. Similar material is bornite, Cu₅FeS₄.

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Sandstone

Arenite (a specific type of sandstone with less than 15% matrix)

Limestone

Calcium Carbonate (CaCO3)

Quartz

Quartz (SiO₂)

Milky quartz with dark host-rock inclusions

Quartz (SiO₂), likely in a granitic or metamorphic matrix

Serpentine-rich metamorphic stone

Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile) with possible quartz, magnesite, and magnetite

Red Jasper

Red Jasper (variety of Chalcedony, SiO₂)

Sandstone

Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)

Tumbled serpentine

Serpentinite; chiefly serpentine-group minerals, Mg3Si2O5(OH)4

BROWN GRANITE (likely 'Tan Brown' or similar)

Granite (specifically a variety rich in orthoclase feldspar, often with biotite and possibly hornblende)

Raw calcite specimen

Calcite, calcium carbonate (CaCO₃)

Fossil Coral

Phylum Cnidaria / Rugosa or Tabulata

Granite (weathered pebble)

Granite (plutonic igneous rock)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Quartz

Quartz (SiO2, Silicon Dioxide)

Chert (Yellow/Brown variety)

Chert (SiO2)

Iron-stained milky quartz

Quartz (SiO₂), mainly massive or vein quartz, with reddish-brown iron-oxide staining and possible minor feldspar or other vein minerals

Granite

Granite

Chert (Fossiliferous)

Silicon dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Coral (Precious Coral)

Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).

Sandstone

Arenite (SiO2 based with various mineral cements)

Tumbled green-brown stone, likely serpentine

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite

Weathered serpentinite (likely serpentine-rich rock)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite and accessory minerals

Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock

Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt

Jasper (yellow/cream variety)

SiO₂ (Cryptocrystalline Quartz)