Sedimentary And Metamorphic

Chalcedony (Agate) Pebble

Silicon Dioxide (SiO2)

Green Aventurine

Silicon dioxide (SiO2) with fuchsite inclusions

Quartz

Silicon Dioxide (SiO2)

Quartz Vein in Pelite (Metamorphic Rock)

Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)

Mineral and rock specimen collection

Assorted geological materials, including amethyst, agate, azurite, calcite, feldspar, garnet, jasper, malachite, pyrite, quartz varieties, and others

Faceted clear gemstone, likely glass or cubic zirconia

Undetermined; could be synthetic cubic zirconia (ZrO₂) or cut glass (silica-based)

Rounded quartz-rich cobble

Likely quartzite or quartz-rich sandstone; exact identification requires a fresh break or hardness test

Light-colored pebble, likely quartzite or weathered limestone

Indeterminate from image; possible quartzite (microcrystalline SiO₂)

Mixed rock and mineral collection

Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials

Pyrite-bearing rock (likely pyrite-rich schist or sulfide ore)

Pyrite (FeS₂) in a fine-grained host rock; exact host cannot be determined from the image

Pyrite-bearing rock (likely pyrite in a quartz-rich matrix)

Pyrite (FeS₂), with a light-colored quartz-rich host; exact host rock is unclear from the image

Clear quartz crystals

Quartz (silicon dioxide, SiO₂)

Small red-brown mineral or rock fragment

Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide

Native Silver Nugget

Silver (Ag)

Pyrite

Iron Pyrite (FeS2)

Tumbled hematite (likely hematite-rich ironstone)

Hematite, Fe₂O₃; possibly mixed with magnetite or goethite

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Limonite pseudomorph after Pyrite

Goethite/Limonite FeO(OH)·nH2O

Yellow Agate

Agate (Varietal form of Chalcedony/Quartz, SiO2)

Small weathered mineral/rock fragment

Indeterminate; possibly quartz-bearing feldspathic rock or calcite-rich specimen

Green Opal

Hydrated Silica (SiO2·nH2O)

Pyrite-bearing rock, possibly pyrite-rich schist or quartzite

Pyrite (iron disulfide, FeS₂) in a fine-grained metamorphic or quartz-rich matrix

Jasper

Silicon dioxide (SiO2)

Jasper (Red and Yellow)

Silicon Dioxide (SiO2) with iron oxide impurities

White Quartz Star-cut crystal

Silicon Dioxide (SiO2)

Jasper

Microcrystalline Quartz (SiO2)

Pyrite on Quartz matrix

Iron Disulfide (FeS2) on Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Pyrite-bearing rock

Likely pyrite (FeS₂), possibly with quartz or other sulfide minerals

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Turquoise (Dyed Howlite/Magnesite imitation)

CuAl6(PO4)4(OH)8·4H2O (Target mineral) / MgCO3 (Magnesite substrate)

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Small pale mineral fragment, likely quartz or calcite

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing

Likely weathered sandstone or metasandstone

Quartz-rich sandstone (possibly weakly metamorphosed metasandstone)

Raw quartz fragment

Quartz (SiO₂), likely milky or included quartz

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Brecciated Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Quartz Vein in Hematitic Siltstone

Hydrothermal Quartz (SiO2) in Ferriferous Matrix

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Weathered iron-stained quartzite or chert nodule

Siliceous rock composed chiefly of microcrystalline quartz (SiO₂), with iron-oxide staining and possible clay/minor carbonate minerals

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions