Mineralological Specimen

Blue-green fluorite (rough crystal)

Fluorite, calcium fluoride (CaF₂)

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

Polished banded agate

Agate, a banded variety of microcrystalline quartz (SiO₂)

Polished/tumbled pale-yellow stone, possibly calcite

Likely calcite (CaCO₃); identification is uncertain from the image alone

Polished red jasper (possibly carnelian/chalcedony)

Jasper, an opaque microcrystalline variety of quartz (SiO₂); exact identification is uncertain from the image

White Quartz Pebble

Silicon Dioxide (SiO2)

Small pale pebble, possibly quartz or feldspar

Unidentified silicate; appearance alone cannot distinguish quartz (SiO₂) from feldspar

Likely scoria (vesicular basalt)

Scoria, typically basaltic; composed mainly of plagioclase, pyroxene, and sometimes olivine

Banded calcite (likely travertine or flowstone)

Calcite, CaCO₃; possibly speleothem/travertine

Dyed Agate (Tumbled)

Silicon Dioxide (Chalcedony variety, artificially dyed)

Biotite mica (likely)

Biotite, a mica-group mineral; approximate formula K(Mg,Fe)₃AlSi₃O₁₀(F,OH)₂

Chert (Carnelian/Jasper variety)

Microcrystalline Quartz (SiO2)

Sulfur-bearing Limestone (Solfatara Specimen)

Sulfur-rich Bio-limestone (Calcium Carbonate with Native Sulfur, S8)

Coarse-grained metamorphic rock, likely amphibolite or hornblende gneiss

Amphibolite; predominantly hornblende amphibole and plagioclase feldspar, possibly with quartz and biotite

Clear Quartz

SiO2 (Silicon Dioxide)

Fossilized Bone Chunk

Permineralized Vertebrate Bone (indeterminant)

Brachiopod Fossil in Limestone

Phylum Brachiopoda embedded in sedimentary rock

Fossilized Oyster in Flint

Gryphaea or Exogyra embedded in SiO2 (Flint/Chert)

Quartz Geode with Calcite

Silicon Dioxide (SiO2) and Calcium Carbonate (CaCO3)

Metallic Ornament / Jewelry

N/A - This is an artificial object, not a geological specimen.

River Pebble (Likely Quartzite or Chalcedony)

Silicon Dioxide (SiO2) - granular metamorphic variety

Sandstone

Sedimentary Rock (Quartz Sandstone)

Blue Goldstone

Man-made glass with cobalt and metal flecks

Quartz Pebble (Quartzite Pebble)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Muscovite Mica Schist

Metamorphic rock rich in muscovite mica (KAl2(AlSi3O10)(F,OH)2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Sandstone

Arenite

Agate

Silicon dioxide (SiO2)

Tumbled/polished aventurine (likely green quartzite)

Quartzite, predominantly quartz (SiO₂), colored by fuchsite or chlorite inclusions

Black river rock, likely basalt

Basalt (fine-grained mafic volcanic rock; identification from photo is tentative)

Pale limestone or calcite-rich rock

Calcite (CaCO₃), likely micritic limestone

Quartz-rich rock fragment, possibly mica-bearing pegmatite

Likely quartz–feldspar–mica aggregate; exact identification requires testing

Dark rock specimen (possibly slate or shale)

Unidentified fine-grained rock; slate is foliated metamorphosed shale, while shale is sedimentary mudrock

Orbicular granite (likely weathered granitic rock with feldspar phenocryst)

Granite; chiefly quartz, K-feldspar, plagioclase, and biotite/hornblende

Biotite-rich schist with garnet-like inclusion

Mica schist; predominantly muscovite/biotite mica, quartz, and feldspar, with a possible garnet or weathered mafic fragment

Unidentified gray-green rock specimen

Possibly banded gneiss or another foliated metamorphic rock; identification is uncertain from the image

Granite (likely weathered granitic rock)

Granite; primarily quartz (SiO₂), feldspar, and mica/amphibole