Sedimentary Rock (Altered)

Malachite-bearing copper ore

Malachite, Cu₂CO₃(OH)₂, likely with chrysocolla and limonite/matrix minerals

Echinoid Fossil in Flint or Chert Nodule

Echinoidea embedded in sedimentary silica (SiO2)

Unakite-like jasper / epidote–feldspar rock

Epidote–feldspar–quartz aggregate; commonly marketed as unakite or brecciated jasper

Lapis Lazuli

Lapis Lazuli (a rock, not a single mineral; primary mineral is Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2

Lapis Lazuli

Complex metamorphic rock primarily composed of Lazurite ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2), Calcite, and Pyrite

Lapis Lazuli

Complex metamorphic rock consisting mainly of Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite

Weathered basaltic rock

Basalt, likely amygdaloidal or altered basalt (plagioclase–pyroxene ± olivine)

Polished Picasso jasper

Silicified carbonate rock, commonly marketed as Picasso jasper; composition varies and is not a single mineral species

Tiger’s eye

Quartz variety, primarily silicon dioxide (SiO₂); fibrous quartz pseudomorph after crocidolite asbestos

Tumbled greenstone / altered basalt pebble

Fine-grained mafic volcanic rock, likely basalt or greenstone; commonly composed of plagioclase, pyroxene, chlorite, epidote, and iron oxides

Chrysocolla (Copper Ore matrix)

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Chrysocolla-bearing copper ore

Chrysocolla, hydrated copper aluminosilicate (approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O), likely mixed with copper oxides and quartz/matrix minerals

Shale or Slaty Mudstone

Argillaceous sedimentary rock

Turquoise

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

Dendritic limestone or marble slab

Manganese-oxide dendrites in carbonate rock, likely calcite (CaCO₃)

Rounded weathered pebble, likely sandstone or altered limestone

Indeterminate clastic carbonate/siliciclastic rock; exact identification requires a fresh surface and tests

Ironstone (likely Limonite or Goethite nodule)

Hydrothermally altered Ferric Hydroxide (FeO(OH)·nH2O)

Rounded brown pebble, likely weathered basalt or lateritic rock

Probable fine-grained basalt; exact identification uncertain from the photograph

Lapis Lazuli (Lazurite crystals on Marble)

Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]

Tiger's Eye

Silicon dioxide (SiO2) with fibrous inclusions of crocidolite

Rounded river pebble, likely weathered basalt or andesite

Fine-grained mafic volcanic rock; probable basalt (plagioclase + pyroxene ± olivine, altered by weathering)

Unakite

Epidote-Feldspar rock (specifically, a variety of granite)

Shale

Argillite / Shale

Weathered basalt pebble

Basalt, a fine-grained mafic volcanic rock; likely olivine-bearing basalt

Citrine (Heat-Treated Amethyst)

Silicon Dioxide (SiO2)

Smoky Quartz

SiO2 (Silicon Dioxide)

Unakite

Epidote-Feldspar rock

Chrysocolla-bearing copper ore

Chrysocolla, hydrated copper phyllosilicate (approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O), likely mixed with malachite and/or turquoise

Turquoise

Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Azurite–malachite-bearing copper ore

Azurite (Cu₃(CO₃)₂(OH)₂) with malachite (Cu₂CO₃(OH)₂), in a copper-rich host rock

Quartz-bearing greenstone (probable epidote–quartz rock)

Epidote–quartz schist/greenstone; chiefly quartz (SiO₂) and epidote [Ca₂(Al,Fe)₃(SiO₄)₃(OH)], with possible chlorite and feldspar

Rhodonite

Rhodonite, manganese inosilicate — MnSiO₃; the specimen may include quartz, feldspar, and black manganese-oxide minerals in the matrix

Tiger's Eye

Silicon dioxide with crocidolite fibers (SiO2 with chrysotile amphibole inclusions)

Likely serpentine (serpentinite) pebbles

Serpentine-group minerals, chiefly antigorite, lizardite, and/or chrysotile; commonly Mg₃Si₂O₅(OH)₄, sometimes containing magnetite, chromite, and minor carbonate minerals

Weathered vesicular basalt (probable volcanic bomb)

Basalt, primarily plagioclase feldspar, pyroxene, and olivine

Shale / Mudstone

Laminated Mudrock (Siliciclastic Sedimentary Rock)

Shale (Beach-worn)

Laminated Pelite (primarily clay minerals and quartz)

Possible basalt or iron-rich river pebble

Fine-grained mafic rock, likely basalt (plagioclase–pyroxene ± olivine, with iron oxides)

Fossilized bivalve shell fragment

Fossil mollusk shell, likely a pectinid or related bivalve; original shell composed mainly of aragonite or calcite, now partly mineralized

Tumbled sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; likely a sodalite-rich nepheline-syenite fragment

Malachite

Malachite — Cu₂CO₃(OH)₂, hydrated copper carbonate

Shale

Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)