Man Made Material

Greenstone / Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)

Vesicular Basalt (Iron Scoria)

Aphanitic Mafic Igneous Rock with Vesicular Texture

Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)

Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement

White calcite (likely tumbled calcite or marble fragment)

Calcite, calcium carbonate (CaCO₃); if the specimen is granular and rock-like, it may be marble, a calcite-rich metamorphic rock

Iron-rich sandstone or laterite

Ferruginous sandstone; mainly quartz (SiO₂) cemented or stained by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

Likely weathered gray-green stone, possibly serpentinite

Serpentinite (predominantly serpentine-group minerals; identification uncertain from image)

Quartz

Silicon Dioxide (SiO2)

Polished/tumbled jasper, likely ocean jasper or brecciated jasper

Jasper: microcrystalline quartz (SiO₂) with iron oxides and other silicate impurities

Schist

Mica Schist (primarily consisting of muscovite, biotite, and quartz)

Diamond

Diamond (C)

Limonite (Ironstone Concretion)

Limonite (FeO(OH)·nH2O)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Quartzite Pebble

Metamorphic Quartz (SiO2)

Mixed river gravel (alluvial conglomeratic sediment)

Polymictic alluvium; composition includes quartz, feldspar, chert, granite, basalt, and metamorphic rock fragments

Granite

Phaneritic Felsic Igneous Rock

Quartzite

Quartzite (SiO2)

Crushed Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Sandstone

Sandstone (lithified arenite/wacke)

Jasper (Red/Yellow)

Silicon Dioxide (SiO2) with impurities

Sandstone (with Iron Staining)

Arenite (Siliclastic sedimentary rock)

Quartz-bearing granite or granitic pegmatite

Felsic intrusive rock, chiefly quartz (SiO₂), feldspar, and minor mica

Quartz geode clusters

Microcrystalline quartz (SiO₂), with possible chalcedony and minor iron-oxide staining

Jasper

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Ferruginous Sandstone

Sandstone, Iron-rich

Sandstone (Red)

Arenite (primarily SiO2 with Iron Oxide staining)

Olivine in Basalt matrix

Peridotite (Mg, Fe)2SiO4

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartz-rich breccia or vein quartz with dark inclusions

Milky quartz (SiO₂), likely brecciated and cemented with iron oxides and dark mica/amphibole minerals

Quartz (likely macrocrystalline variety)

Quartz (SiO₂)

Red Sandstone

Ferruginous Sandstone

Red Jasper (with Chert/Quartz)

Silicon Dioxide (SiO2)

Chert (Agate/Flint variant)

Microcrystalline Quartz (SiO2)

Serpentinized ultramafic rock (serpentinite)

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

Vuggy Quartz on Matrix

Silicon Dioxide (SiO2)

Granite

Phaneritic plutonic rock (Quartz + Feldspar + Mica)

Quartzite or Quartz Vein Material

SiO2

Limestone

Calcium Carbonate (CaCO3)

Tumbled chalcedony or carnelian

Microcrystalline quartz (SiO₂), likely iron-bearing chalcedony

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)