Metamorphic Or Igneous (Context Dependent)

Milky Quartz (Water-worn pebble/nodule)

Quartz (Silicon Dioxide - SiO2)

Ruby (Raw Corundum)

Corundum (Al2O3:Cr)

Ferruginous Sandstone

Ferruginous Sandstone (Quartz Arenite with Iron Oxide cement)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Red Jasper

Silicon Dioxide (SiO2) with Iron inclusions

Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)

Calcite

Quartz (Iron-stained or Ferruginous)

Silicon Dioxide (SiO2)

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) in Carbonate Matrix

Chert / Flint Arrowheads

Cryptocrystalline Quartz (SiO2)

Slag (Industrial)

N/A (Anthropogenic Slag)

Sandstone (Micaceous Sandstone)

Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)

Milky Quartz (with Iron staining)

Silicon Dioxide (SiO2)

Red gemstone ring, likely garnet or synthetic ruby

Possibly almandine garnet (Fe₃Al₂(SiO₄)₃) or corundum/ruby (Al₂O₃); image alone cannot distinguish

Emerald in Matrix

Emerald (Beryllium Aluminum Silicate), Be3Al2(SiO3)6

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Bivalve Fossil (Clam)

Class Bivalvia (e.g., Mercenaria or similar genus), composed of CaCO3 (Aragonite/Calcite)

Milky Quartz

Silicon Dioxide (SiO2)

Seraphinite

Clinochlore (Mg,Fe)5Al(AlSi3O10)(OH)8 - specific variety for Seraphinite due to its fibrous inclusions and chatoyancy.

Iron-Nickel Meteorite fragment

Siderite (meteoritic iron), composed primarily of Kamacite (α-(Fe,Ni)) and Taenite (γ-(Fe,Ni))

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Fossiliferous Limestone with Crinoid Stem fragment

Calcite (CaCO3) containing Crinoidea fossils

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Ironstone Concretion (Moqui Marble type)

Ironstone Concretion (Fe2O3 with SiO2 core)

Obsidian arrowhead flakes

Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)

Diamond

C (Carbon)

Red Quartz

Silicon Dioxide (SiO2) with Hematite inclusions

Faceted yellow gemstone, likely citrine

Citrine (quartz), SiO₂; possibly yellow sapphire or synthetic glass without testing

Black Jasper

Silicon dioxide (SiO2) with carbon/mineral inclusions

Ruby

Corundum (Al₂O₃) with Chromium (Cr)

Lepidolite

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

Black Jasper

Black Jasper (Silicate mineral - SiO2)

Coprolite

Fossilized Feces

Chert (Cream Variety)

Microcrystalline silica (SiO2)

Red Sandstone

Arenite (primarily SiO2 with Fe2O3)

Milky quartz vein fragment

Quartz, silicon dioxide (SiO₂)

Rose Quartz

Silicon Dioxide with trace inclusions of dumortierite or titanium (SiO2)

White quartz-rich pebble

Likely quartzite or milky-quartz pebble (SiO₂)

Blue Sapphire

Corundum (Al2O3) with traces of Iron and Titanium

Milky quartz vein fragment

Quartz (silicon dioxide, SiO₂), massive/microcrystalline variety

Jasper Marble

Silicon Dioxide (SiO2) with Impurities

Bull Quartz (Milky Quartz)

Silicon Dioxide (SiO2)