Mineral In A Matrix (Likely Quartz Or Feldspar)

Rounded quartz-rich pebble, possibly granite or gneiss

Indeterminate granitoid; likely quartz–feldspar–biotite aggregate

Weathered granite or granitic gneiss pebble

Granite; primarily quartz, potassium feldspar, plagioclase, and mica

Copper-bearing Quartz (likely Chrysocolla or Malachite staining)

Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock

Granite

Granite

Weathered quartz-rich granitoid (likely granite or granodiorite)

Granite–granodiorite; chiefly quartz (SiO₂), feldspar, and minor mica/amphibole

Dalmatian Jasper

Dalmatian Stone (a porphyritic peralkaline igneous rock)

Granite (likely weathered granite fragment)

Coarse crystalline felsic intrusive rock, chiefly quartz, potassium feldspar, plagioclase, and minor biotite or hornblende

Granite Pebble

Granite (phaneritic igneous rock)

Foliated metamorphic rock, likely biotite schist

Mica schist, chiefly quartz, feldspar, and biotite mica

Schorl (Black Tourmaline) in Quartz Matrix

Schorl: NaFe3Al6(BO3)3Si6O18(OH)4 (Complex Borosilicate)

Dalmatian Jasper

Dalmatian Stone (Felsite with Arfvedsonite/Tourmaline)

Granite Pebble

Granite (Felsic Intrusive Igneous Rock)

Polished river pebble, likely granite or granitic gneiss

Quartz–feldspar–mica aggregate; possibly biotite granite (compositionally near granite)

Mixed rock and mineral gravel

Predominantly granite/granodiorite, basaltic rocks, quartz, and possible gneiss; exact identification is uncertain from the image

Calcite on Limestone

Calcium Carbonate (CaCO3) on Sedimentary Rock

Garnet-bearing metamorphic rock, likely mica schist

Biotite–garnet schist; commonly includes quartz, feldspar, biotite, and almandine garnet

Dalmatian Jasper

Peralkaline Quartz-feldspathic Rock (Arfvedsonite-bearing)

Honey quartz crystal cluster

Quartz, silicon dioxide (SiO₂), likely iron-stained or inclusion-rich quartz

Raw smoky quartz with dark mineral inclusions

Quartz (SiO₂), likely smoky quartz; dark inclusions may be chlorite, tourmaline, or iron/manganese oxides

Granite (likely biotite granite or granodiorite)

Coarse-grained granitoid composed mainly of quartz, feldspar, and dark biotite/hornblende

Granite

Phaneritic plutonic igneous rock (SiO2 range 65-75%)

Weathered granite or granitic gneiss

Quartz–feldspar–mica granitic rock; possibly gneiss if foliation is present

Sandstone

Clastic sedimentary rock (primarily Quartz and Feldspar)

Mixed rock and mineral specimen collection

Mostly undetermined from the photograph; apparent quartz-rich rocks, sandstone, granite/gneiss, and possibly iron-oxide-bearing specimens

Banded agate (likely carnelian/chalcedony)

Microcrystalline quartz, SiO₂; iron-stained chalcedony

Polished brecciated jasper (likely septarian or iron-rich jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and possibly calcite or other rock fragments

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Chrysocolla in Matrix

Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix

Gold-bearing quartz or iron-stained sulfide specimen

Native gold (Au), possibly in quartz with limonite/goethite and sulfide remnants

Likely weathered granite or granitic pegmatite

Granite; mainly quartz (SiO₂), feldspar, and mica, with possible iron-oxide staining

Graywacke

Lithic Sandstone (Graywacke)

Weathered granite or granitic gneiss pebble

Granite, primarily quartz, feldspar, and mica; possibly weakly foliated gneiss

Granite

Phaneritic plutonic rock (High silica)

Sandstone

Arenite (primarily SiO2)

Dalmatian Jasper

Peralkaline Quartz-Feldspar Porphyritic Rock (Dalmatian Stone)

Sandstone (likely Arkose)

Arenite (Feldspathic Sandstone / Arkose)

Diorite

Plutonic Igneous Rock (NaAlSi3O8, CaAl2Si2O8)

Unidentified gray-brown stone

Likely fine-grained quartz–feldspar rock; exact identification is not possible from this close, blurred image

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Veined quartz-bearing metamorphic rock

Likely quartzite or siliceous schist with iron-oxide staining

Amygdaloidal Basalt

Amygdaloidal Basalt (with Epidote and Feldspar/Zeolite infill)

Amygdaloidal Basalt

Basalt with secondary mineral infilling