Mineral With Artificial Coating

Purple Agate (Dyed Chalcedony)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Porphyritic Igneous Rock with Iron Oxide Weathering

Weathered Porphyry (containing Quartz, Feldspar, Amphibole/Biotite, and Hematite/Limonite)

Iron-stained quartz-bearing rock

Likely quartz with iron-oxide staining; exact rock type cannot be determined from the image

Polished leopard jasper (likely ocean jasper)

Silicified microcrystalline quartz/chalcedony; mainly SiO₂ with iron-oxide inclusions

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Quartz (Iron-Stained / Vein Quartz)

Silicon Dioxide (SiO2)

Quartz with Mica inclusions (likely Iron-stained)

Silicon Dioxide (SiO2) with Phyllosilicates

Possible iron-stained quartzite or sandstone fragment

Quartzite (mostly SiO₂), possibly ferruginous sandstone

Limonite (Hydrated Iron Oxide / Bog Iron)

FeO(OH)·nH2O

Polished labradorite heart pendant

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

Iridescent bismuth crystal

Bismuth (Bi), commonly laboratory-grown and oxidized

Dyed and polished agate slice

Agate, a banded microcrystalline variety of chalcedony (SiO₂), commonly quartz with minor impurities

Quartz (Druzy)

Silicon Dioxide (SiO2)

Iron-stained rock fragment, possibly quartz-rich

Unidentified quartz-rich rock with iron-oxide staining (likely hematite/goethite)

Likely weathered ironstone or iron-stained sandstone fragment

Ferruginous sandstone/ironstone, chiefly quartz (SiO₂) with iron oxides such as hematite and goethite

Weathered limestone pebble

Limestone, chiefly calcite (CaCO₃)

Druzy Quartz on Sandstone

Silicon Dioxide (SiO2) with Quartz crystals

Milky quartz with iron staining

Quartz (SiO₂), likely massive vein quartz

Aura Quartz

Silicon dioxide coated with titanium and other metals (SiO2)

Small metallic-looking rock fragment

Uncertain; possibly galena-bearing ore or mica-rich schist

Titanium Aura Quartz

Titanium bonded Silicon Dioxide (SiO2 + Ti)

Vesicular basalt (possibly weathered lava rock)

Basalt; chiefly plagioclase, clinopyroxene, and olivine, with iron oxides

Likely garnet-bearing metamorphic fragment

Uncertain; possibly almandine garnet in mica schist or amphibolite

Uncertain polished mineral specimen

Indeterminate; possibly quartz or feldspar with iron-oxide staining

Sandstone (with iron staining)

Quartz Arenite / Ferruginous Sandstone

Druzy Quartz on Limestone

Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)

Pyrite

Iron Sulfide (FeS2)

Tumbled quartz bead bracelet

Quartz (SiO₂), likely milky or rose quartz

Red Sandstone

Ferruginous Sandstone (SiO2 with Fe2O3)

Red Sandstone

Arenite (primarily Quartz SiO₂ with Hematite Fe₂O₃ staining)

Peridot (Olivine)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Sandstone (Iron-stained)

Arenite with Limonite/Hematite staining

Silicon Carbide

Silicon Carbide (Moissanite / Carborundum), SiC

White Quartz Sphere

Silicon Dioxide (SiO2)

White quartz pebble

Quartz (silicon dioxide, SiO₂)

Tumbled quartz-rich pebble, possibly calcite or quartzite

Most likely microcrystalline quartz (SiO₂); carbonate identification would require testing

Chrysocolla-bearing copper ore

Chrysocolla (hydrated copper aluminosilicate), likely with malachite, azurite, or limonite

Red Sandstone

Quartzose Sandstone

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Quartz (Druzy/Macro-crystalline)

Silicon Dioxide (SiO2)

Basalt with pale mineral veins/coating

Likely vesicular or altered basalt, with calcite or zeolite minerals

Milky quartz with iron staining

Quartz, SiO₂; likely massive milky quartz with brown iron-oxide staining