Sedimentary Or Metamorphic (Low Grade)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide, FeS2

Pyrite Cube

Iron Sulfide (FeS2)

Red Jasper with Quartz Veining

Microcrystalline Quartz (SiO2)

Serpentinite

Serpentine rock (Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al,Fe)2O5(OH)4

Polished greenstone pebble

Greenstone (chlorite–epidote–actinolite-rich metamorphosed mafic rock)

Rounded green-gray pebble, likely greenstone

Greenstone (metamorphosed mafic rock; commonly chlorite- and actinolite-bearing)

Greenstone with quartz veins

Chlorite- and epidote-bearing metabasalt (greenstone), cut by quartz veins

Mottled green-and-white rock fragment

Possibly serpentinite or a chlorite-rich metamorphic rock; identification is uncertain from the photograph alone.

Greenstone pebble (likely metamorphosed basalt)

Greenstone, commonly chlorite- and actinolite-bearing metabasalt

Greenstone / altered basalt (probable)

Chlorite–epidote–actinolite-rich metabasalt; exact identification requires testing

Calcite-rich limestone (likely crystalline limestone/marble)

Calcite, CaCO₃; likely recrystallized carbonate rock

Polished tiger’s-eye

Quartz variety: fibrous golden-brown chalcedonic quartz, SiO₂

Likely polished blue-gray stone, possibly labradorite or slate

Tentatively labradorite (plagioclase feldspar, NaAlSi₃O₈–CaAl₂Si₂O₈) or blue-gray slate; identification is limited by the close-up image

Foliated metamorphic rock (likely slate or phyllite)

Slate/phyllite; chiefly quartz, mica, and chlorite

Banded Chert or Unakite-like Rock

Epidotized Granulite or Jasperoid Chert

Onyx (Calcite Onyx / Mexican Onyx)

Calcium Carbonate (CaCO3)

Likely micaceous metamorphic rock fragment

Probable phyllite or mica schist; quartz–muscovite-rich assemblage

Greenstone

Metabasalt / Greenschist

Anthracite Coal

Anthracite

Greenstone

Metabasalt (often contains Chlorite, Actinolite, and Epidote)

Citrine

Quartz (Silicon Dioxide, SiO2)

Jadeite Jade

Jadeite (NaAlSi2O6)

Likely polished tiger’s-eye with dark matrix

Quartz (SiO₂) with fibrous crocidolite-derived inclusions; possibly an iron-rich jasper or other dark host rock

Epidote and Quartz in Basalt

Epidote [Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)] in Metabasalt

Opal

Hydrated amorphous silica (SiO2·nH2O)

Dark gray metamorphic rock, likely slate or phyllite

Slate/phyllite; chiefly fine-grained mica, chlorite, quartz, and clay-derived minerals

Greenstone

Metamorphosed Mafic Igneous Rock

Schist (Greenschist / Mica Schist)

Schist (variable mineral composition, commonly containing quartz, feldspar, mica, chlorite)

Siltstone

Siltstone (primarily SiO2 with Fe2O3)

Chert (or potentially massive Quartz/Quartzite)

SiO2 (Silicon Dioxide)

Quartz-rich sandstone or quartzite pebble

Likely quartz arenite sandstone; possibly low-grade quartzite, composed mainly of SiO₂

Bloodstone (Heliotrope)

SiO2 (Cryptocrystalline Quartz / Chalcedony)

Polished tiger’s-eye

Quartz-rich aggregate with chatoyant fibrous crocidolite pseudomorphs; mainly SiO₂

Polished tiger’s eye

Quartz variety, SiO₂, with parallel fibrous amphibole pseudomorphs (crocidolite)

Limonite stained Sandstone

Sedimentary rock with Goethite/Limonite (FeO(OH)·nH2O)

Jasper

Silicon dioxide (SiO2) with impurities

Nephrite Jade

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

Quartz-rich rock fragment

Milky quartz, primarily silicon dioxide (SiO₂), possibly quartzite or a feldspar-bearing vein rock

Greenschist (Chlorite Schist)

Greenschist (containing chlorite, actinolite, and epidote)

Glauconitic Sandstone

Glauconitic Sandstone (Greensand)

Siltstone with Iron Staining

Siltstone (primarily SiO2 with Fe2O3 staining)