Man Made Material (Metal)

Quartzite (Potentially Ferruginous)

Quartzite (SiO2)

Celestite (Celestine)

Strontium Sulfate (SrSO4)

Celestite (Celestine)

Strontium Sulfate (SrSO4)

Quartzite

Quartzite (SiO2)

Quartzite Pebble

Quartzite (primarily SiO2)

Celestite (Celestine)

Strontium sulfate (SrSO4)

Ferromanganese Nodule

Polymetallic Nodule (composed primarily of MnO2 and Fe2O3)

Chert (Basanite variety) with Quartz Vein

Microcrystalline Quartz (SiO2)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Granite featuring Quartz Vein

Granite with hydrothermal silica (SiO2) intrusion

Corundum (Sapphire variant)

Aluminium oxide (Al2O3)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Amethyst

SiO2 (Silicon Dioxide with Iron impurities)

Agate (specifically, multi-colored or pastel-dyed agate)

Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).

Quartzite

Quartzite (primarily SiO2)

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Quartzite

Quartzite (primarily SiO2)

Quartzite (Yellow/Iron-Stained)

Quartzite (SiO2 with Iron Oxide impurities)

Lepidolite with Quartz

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2

Biotite Gneiss

Gneiss (complex mixture including Biotite K(Mg,Fe)3AlSi3O10(F,OH)2 and Quartz/Feldspar)

Chert (Flint Nodular Variety)

Microcrystalline Quartz (SiO2)

Graphite

Graphite (Carbon, C)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Serpentinite

Serpentinite (composed primarily of serpentine group minerals like lizardite, chrysotile, or antigorite; Mg3Si2O5(OH)4)

Serpentinite

Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)

Gold Ore in Quartz

Native Gold (Au) in Quartz (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

Blue Calcite

Calcium Carbonate (CaCO3)

Granite

Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)

Granite

Granite (a phaneritic intrusive igneous rock)

Granite

Phaneritic Felsic Igneous Rock

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Granite

Granite (Silicic Intrusive Igneous Rock)

Granite

Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)

Granodiorite

Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)

Blue Chalcedony

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Bivalve Fossil (Shell Fragment)

Class Bivalvia (Calcium Carbonate - CaCO3)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Banded Chert

Microcrystalline Quartz (SiO2)

Diamond (in a jewelry setting)

Carbon (C)

Silver (Jewelry Specimen)

Native Silver (Ag)