Mixed: Igneous And Sedimentary

Agate

Chalcedony (SiO2)

Agate

Silicon Dioxide (Chalcedony), SiO2

Agate

Silicon dioxide (chalcedony variety), SiO2

Epidosite (Epidote-rich rock)

Epidosite (consisting primarily of Epidote: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Tumbled pastel gemstone bead strand

Likely dyed or heat-treated quartz/chalcedony varieties, possibly rose quartz, amethyst, and agate

Granite

Granite (composed of quartz, potassium feldspar, plagioclase, and mica/biotite)

Yellow-brown jasper or silicified volcanic rock

Microcrystalline quartz (chalcedony), SiO₂, likely jasper

Iron-rich ochre (red/brown hematite pigment)

Hematite, Fe₂O₃, likely mixed with clay and quartz grains

Tumbled green jasper (probable serpentine-rich stone)

Jasper, microcrystalline quartz (SiO₂), possibly mixed with serpentine or chlorite

Grey Chalcedony (Agate)

Silicon Dioxide (SiO2)

Botryoidal limonite/goethite nodule

Limonite (largely goethite, FeO(OH), with hydrated iron oxides)

Magnetite-rich black sand

Magnetite (Fe₃O₄), likely mixed with other heavy minerals

Metallic sulfide mineral specimen, likely pyrite

Pyrite (FeS₂), possibly mixed with marcasite or another iron sulfide

Pyrite-bearing sulfide ore (likely pyrite with iron oxides)

Pyrite, FeS₂, possibly mixed with limonite/goethite and other sulfides

Polished Tumbled Fluorite (or Dark Amethyst)

CaF2 (Calcium Fluoride) / SiO2 (Silicon Dioxide)

Tumbled quartz (likely milky or rose quartz)

Quartz, silicon dioxide (SiO₂)

Epidote

Epidote (Ca2(Al,Fe)3(SiO4)3(OH))

Tumbled jasper and agate assortment

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral impurities

Uncertain blue-white mineral fragment

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

Magnetite sand (black iron-oxide sand)

Magnetite, Fe₃O₄; commonly mixed with ilmenite and other heavy minerals

Mixed rounded river pebbles, probably quartz-rich metamorphic and volcanic rocks

Predominantly quartzite/metachert, with possible rhyolite, sandstone, and iron-stained quartz; exact species cannot be determined confidently from the image

Carnelian (Carnelian Agate)

Carnelian (Silicon Dioxide - SiO2)

Natural gemstone and mineral collection

Mixed specimens, including turquoise, tiger’s eye, amethyst, fluorite, pyrite, garnet, rose quartz, lapis lazuli, obsidian, rhodonite, red corundum, labradorite, calcite, lepidolite, sodalite, apatite, and others

Carnelian Agate

Chalcedony (SiO2) with iron oxide inclusions

Iron-rich sulfide ore, likely pyrite-bearing gossan

Pyrite (FeS₂), possibly mixed with iron oxides/hydroxides and other sulfides

Dyed Agate

Chalcedony (SiO2)

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Yellow quartz fragment (likely citrine or iron-stained quartz)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Multi-gemstone Quartz and Fluorite Bracelet

Silicon Dioxide (SiO2) and Calcium Fluoride (CaF2)

Epidote

Epidote (Ca2(Al2,Fe3+)3(SiO4)3(OH))

Sodalite

Sodalite (Na8Al6Si6O24Cl2)

Amazonite (likely mixed with other feldspars/minerals)

Amazonite is a variety of Microcline, which is a tectosilicate mineral, formula KAISi3O8. The mixed beads could include other feldspars or quartz.

Quartz (Druzy)

Silicon Dioxide (SiO2)

Polished blue-gray mineral specimen, likely galena-bearing ore

Galena (PbS), possibly mixed with quartz/calcite and secondary copper minerals

Pegmatite

Igneous Pegmatite (felsic intrusive rock)

Metallic sulfide ore, possibly pyrite-rich

Pyrite (FeS₂), potentially mixed with chalcopyrite, galena, or iron oxides

Metallic sulfide mineral specimen, likely pyrite

Pyrite (iron disulfide, FeS₂), possibly mixed with marcasite or chalcopyrite

Pyrite in Matrix

Iron Sulfide (FeS2)

Yellow-orange quartz (likely citrine or iron-stained quartz)

Quartz, silicon dioxide (SiO₂), colored by iron impurities or irradiation

Dyed Agate

Silicon Dioxide (Chalcedony with artificial colorant), SiO2