Organic Gem Material (Botanical)

Orange fire opal jewelry

Precious opal, hydrated amorphous silica (SiO₂·nH₂O)

Polished ruby-in-zoisite (anyolite), likely

Ruby-bearing zoisite: zoisite Ca₂Al₃(SiO₄)₃(OH), with corundum Al₂O₃ and commonly amphibole

Sugilite

Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)

Blue Goldstone

Aventurine Glass

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Faceted green gemstone, likely peridot

Olivine, gem-quality forsteritic olivine: (Mg,Fe)₂SiO₄

Petrified Wood

Fossilized plant material (Silicon dioxide - SiO2)

Polished watermelon tourmaline

Elbaite tourmaline, Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Diamond (in Matrix)

Carbon (C)

Chrysocolla

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Rhodonite

Rhodonite ((Mn2+,Fe2+,Mg,Ca)SiO3)

Greenstone / Serpentinite Pebble

Serpentinite (Hydrated Magnesium Silicate, Mg3Si2O5(OH)4)

Quartz-rich metamorphic rock (likely mica schist or gneiss)

Quartz–feldspar–mica assemblage; probable biotite schist/gneiss

Small greenish crystal/mineral fragment

Indeterminate; possibly olivine, quartz, or a green gemstone fragment

Turquoise

Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O

Blue Apatite

Calcium Phosphate (Ca5(PO4)3(F,Cl,OH))

White quartz-rich rock, likely quartzite or silicified sediment

Quartzite (mostly quartz, SiO₂); possibly silicified limestone or chert

Polished amethyst or quartz chip

Quartz, silicon dioxide (SiO₂), likely purple amethyst with possible iron-oxide inclusions

Tumbled blue sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Chert (Jasper/Limonitic Chert)

Silicon dioxide (SiO2)

Olivine (Peridot)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Mica-rich quartzite or schist

Quartz–mica metamorphic rock; chiefly SiO₂ with muscovite/biotite mica and minor feldspar

Weathered granite

Granite; quartz–feldspar–biotite aggregate

Quartzite

Quartzite, composed predominantly of recrystallized quartz (SiO₂)

Tumbled orbicular gabbro (likely oceanic gabbro)

Gabbro; chiefly plagioclase feldspar and pyroxene, with possible olivine, amphibole, and magnetite

Weathered porphyritic volcanic rock (likely andesite or basalt)

Fine-grained intermediate-to-mafic volcanic rock; likely andesite/basalt composed mainly of plagioclase, pyroxene, and possibly altered iron-bearing minerals

Serpentinite-bearing quartz vein rock

Serpentinite (antigorite/lizardite) with milky quartz; possible chlorite or epidote alteration

Iron-rich quartzite or weathered ironstone

Quartzite, chiefly SiO₂, with iron-oxide minerals such as hematite/goethite

Tumbled granite or granitic pebble

Granite; primarily quartz, feldspar, and mica (exact variety uncertain from the image)

Weathered iron-rich rock or concretion

Likely limonite/goethite-bearing concretion; exact identification requires testing

Granitic gneiss (weathered, rounded cobble)

Foliated granitoid; primarily quartz, feldspar, and mica (composition commonly approximates granite)

Olivine in Quartz/Feldspar Matrix (Peridotite or Granitic Pegmatite)

(Mg,Fe)2SiO4 (Olivine) with Quartz / Feldspar

Serpentinized ultramafic rock (serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, chromite, talc, and carbonate

Emerald

Beryl, Be₃Al₂(SiO₃)₆, colored green mainly by chromium and/or vanadium

Weathered quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Iron-stained sandstone or weathered ironstone

Ferruginous sandstone; chiefly quartz (SiO₂) cemented or coated by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

Unakite Jasper / Unakite

Altered Granite (containing Epidote, Orthoclase Feldspar, and Quartz)

Yellow faceted gemstone earrings, likely citrine or yellow beryl

Citrine: quartz, SiO₂; possible yellow beryl: Be₃Al₂Si₆O₁₈

Limestone or Sandstone Cobble

Sedimentary rock (Calcium carbonate or Quartz based)

Olivine (Peridot when gem-quality)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Olivine

(Mg, Fe)2SiO4