Mineral (Man Modified)

Slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz

Fluorite

Calcium Fluoride (CaF2)

Weathered gneiss

Banded gneiss, commonly composed of quartz, feldspar, and mica

Tumbled banded stone, likely serpentine or chlorite-rich rock

Probable serpentinite (serpentine-group minerals: Mg₃Si₂O₅(OH)₄), possibly greenstone

Likely tumbled calcite or pale limestone fragment

Calcite (CaCO₃), possibly microcrystalline limestone

Iron-stained quartz (likely quartz vein material)

Quartz, SiO₂, with iron-oxide staining (commonly goethite and/or hematite)

Vesicular basalt (scoria-like volcanic rock)

Vesicular basalt, primarily plagioclase feldspar, pyroxene, and olivine

Carved serpentine pendant

Serpentine-group minerals, commonly antigorite/lizardite (Mg₃Si₂O₅(OH)₄), possibly mixed with chlorite or other inclusions

Quartz-rich pegmatite with smoky/amethyst quartz

Granitic pegmatite; predominantly SiO₂ quartz with feldspar and minor iron/manganese-bearing inclusions

Raw botryoidal goethite/limonite specimen

Goethite (α-FeO(OH)), commonly mixed with limonite (hydrated iron oxides)

Red jasper pebble

Jasper, microcrystalline quartz (SiO₂) colored by iron oxides

Quartz crystal cluster

Quartz (silicon dioxide, SiO₂)

Tumbled quartz (likely milky or included quartz)

Quartz, silicon dioxide (SiO₂)

Likely polished dark stone (identity uncertain)

Undetermined; possibly polished basalt, chert, or another dark silicate rock

Quartz geode

Quartz (SiO₂), likely a quartz-lined geode; the white crystals may include calcite

Howlite

Howlite, Ca₂B₅SiO₉(OH)₅

Citrine

Silicon Dioxide (SiO2)

Limonite / Ironstone Nodule

Limonite (Hydrated iron(III) oxide-hydroxide), FeO(OH)·nH2O

Howlite egg

Howlite, Ca₂B₅SiO₉(OH)₅; hydrous calcium borosilicate hydroxide

Rounded, weathered rock (likely quartz-rich granite or gneiss)

Undetermined quartz–feldspar-rich rock; precise identification requires closer examination

Milky quartz

Quartz (silicon dioxide, SiO₂)

Green Fluorite

Calcium Fluoride (CaF2)

Limonite-stained quartz vein in host rock

Quartz (SiO₂) with iron-oxide/hydroxide staining, commonly goethite and limonite

Blue-green aventurine beads (likely dyed or treated quartz)

Quartz, SiO₂; aventurine is quartz containing fine mineral inclusions

Uncertain blue-white mineral fragment

Possibly calcite or quartz; identification is limited because the specimen is tiny and partly translucent

Green tumbled stone, possibly serpentine

Undetermined; appearance is consistent with serpentine-rich rock (serpentinite), but the image alone cannot confirm identification.

Pegmatite

Granite Pegmatite

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Rainbow Fluorite

Fluorite (Calcium Fluoride, CaF2)

Polished pink quartz specimen

Quartz, SiO₂; possibly rose quartz or pink chalcedony

Olivine in Basalt matrix

Peridotite (Mg, Fe)2SiO4

Brown agate (chalcedony)

Microcrystalline quartz, SiO₂; likely iron-stained chalcedony

Tumbled pale-green stone, possibly serpentine

Indeterminate; appearance is consistent with serpentine-rich rock (serpentine minerals, approximately Mg₃Si₂O₅(OH)₄)

Orbicular Jasper

Silicon Dioxide (SiO2)

Labradorite pendant

Labradorite, a plagioclase feldspar: (Ca,Na)(Al,Si)₄O₈

Rainbow Fluorite

Fluorite (Calcium Fluoride, CaF2)

Calcite crystal cluster

Calcite — calcium carbonate, CaCO₃

Tiny amber-colored crystal or mineral fragment

Indeterminate from image; possibly quartz, citrine, topaz, or iron-stained feldspar

Quartz

Silicon dioxide (SiO2)

Likely lateritic ironstone (limonite/goethite-rich)

Goethite, α-FeO(OH), with possible limonite and clay impurities

Weathered quartz-rich rock, likely quartzite or milky-quartz vein material

Quartzite (dominantly SiO₂), possibly quartz-vein breccia with iron-oxide staining

Banded gneiss

Gneiss; typically quartz–feldspar–mica assemblage