Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Black Veined Jasper (Spiderweb Jasper)

Silicon Dioxide (SiO2)

Quartz (Pebble)

Quartz (SiO₂)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Black Star Diopside (beads)

Diopside (CaMgSi2O6) - a member of the pyroxene group

Jasper (Iron-stained Chalcedony)

SiO2 with Fe2O3 (Iron Oxide) impurities

Greisen

Greisen

Sapphire

Corundum (Al₂O₃) with trace elements causing color variations.

Basalt with Olivine Phenocrysts

Porphyritic Basalt (containing Mg2SiO4 - Fe2SiO4)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Greenstone or Epidote-rich rock

Epidote or Chlorite schist/greenstone

Carnelian

Carnelian Chalcedony (SiO2 with Iron Oxide impurities)

Amethyst (Pale/Lavender variety)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Pebble (river rock/beach pebble)

Pebble (clast size class)

Peridot

Olivine (specific variety: gem-quality forsterite), (Mg,Fe)2SiO4

Asphalt (Bituminous Concrete)

Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)

Jasper

Jasper / Silicon Dioxide (SiO₂)

Granite

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

Black Tourmaline

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

Basalt

Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)

Quartz (likely) or a Quartzite Pebble

Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Obsidian

Obsidian (Volcanic Glass)

Raw Diamond (Rough Uncut)

Diamond (C - pure carbon)

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).

Banded Gneiss

Gneiss (typically quartz, feldspar, mica, amphibole composition)

Marble

Metamorphosed Limestone/Dolomite

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Diamond

Diamond (pure Carbon, C)

Diorite

Diorite

Chrome Diopside

Magnesium Calcium Silicate (MgCaSi2O6) containing Chromium impurities

Sandstone

Sandstone (composed primarily of sand-sized minerals or rock grains)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Serpentinite (Serpentine Rock)

Primarily composed of serpentine group minerals, such as antigorite, chrysotile, and lizardite. Chemical formula for serpentine minerals is (Mg,Fe)3Si2O5(OH)4.

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Quartz (SiO₂)

Clear Quartz Crystal (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Pyrite

Pyrite (Iron Disulfide), FeS2

Scoria

Scoria (a vesicular basalt or andesite)

Pebble (likely Quartzite or Chert)

Clastic Sediment, potentially composed of SiO₂ (Quartz)

Banded Agate (specifically Sardonyx)

Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz