Organic Gem Material (Botanical)

Blue Apatite

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

Lapis lazuli

Lazurite-bearing marble; primarily lazurite (Na₃Ca(Si₃Al₃)O₁₂S) with calcite and pyrite

Green beryl (likely aquamarine-grade beryl)

Beryl, Be₃Al₂Si₆O₁₈; blue-green color is caused mainly by iron

Polished chrysocolla cabochon

Chrysocolla, a hydrated copper silicate (approx. Cu₂H₂Si₂O₅(OH)₄·nH₂O); possibly stabilized or composite material

Diamond ring

Diamond, crystalline carbon (C), likely a faceted mounted stone

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Olivine

(Mg, Fe)2SiO4

Flint (chert), likely brown flint

Microcrystalline quartz/chalcedony (SiO₂)

Amber

Succinite (fossilized resin)

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

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

Mixed rock specimens; likely pink feldspar/quartz and a dark, mica-bearing rock

Tentative visual identification: pink K-feldspar–quartz-rich granite/pegmatite fragments and a dark amphibole- or biotite-rich metamorphic rock; exact identification is uncertain from the image

Banded gneiss pebble

Gneiss, commonly quartz–feldspar–mica banded rock

Rough emerald (beryl) specimens

Emerald, green beryl — Be₃Al₂Si₆O₁₈, colored mainly by chromium and/or vanadium

Quartz-rich sandstone pebble

Sandstone, predominantly quartz (SiO₂) grains cemented by silica or calcite

Greenstone (likely altered basalt or greenschist)

Greenschist-facies mafic rock; commonly chlorite–actinolite–albite ± epidote, or chlorite-altered basalt

Weathered gneiss (probable)

Banded quartz–feldspar–mica gneiss

Polished pink feldspar pebble

Orthoclase or microcline feldspar, KAlSi₃O₈

Quartz crystal cluster with possible chlorite inclusions

Quartz, silicon dioxide (SiO₂), likely with minor chlorite or iron-oxide staining

Milky quartz vein rock

Quartz, SiO₂; likely massive quartz with minor iron-oxide and host-rock material

Rounded pale quartz-rich stone (likely quartzite or milky quartz)

Quartzite, predominantly SiO₂; possibly massive milky quartz

White quartzite pebble

Quartzite; predominantly microcrystalline quartz (SiO₂)

Milky quartz-bearing rock, likely quartzite or silicified limestone

Quartz (SiO₂), possibly in a quartzite or chalcedony-rich matrix

Rounded basalt cobble

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine

Quartz-rich sandstone or quartzite

Quartzite; predominantly crystalline SiO₂, possibly with feldspar and iron-oxide staining

Dark metamorphic rock, likely biotite schist or gneiss

Quartz–feldspar–biotite metamorphic rock; exact identification requires a fresh surface and testing

Olivine (often within Peridotite)

Magnesium iron silicate, (Mg,Fe)2SiO4

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Blue apatite specimen

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Fossilized Bivalve Shell

Class Bivalvia (fossilized)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Sodalite beads

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, likely with minor lazurite/pyrite or calcite inclusions

Dalmatian jasper (often sold as Dalmatian stone)

Porphyritic quartz monzonite or alkali granite, composed mainly of feldspar and quartz with black aegirine/arfvedsonite amphibole-group minerals

Possible weathered sandstone or iron-rich sedimentary rock

Indeterminate; likely quartz-rich sandstone with iron-oxide cement

Chert / Flint

Silicon Dioxide (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Anthracite Coal

Carbon (with trace impurities)

Sandstone

Sandstone (SiO2-dominated clastic rock)

Jasper

Silicon Dioxide (SiO2)

Jasper

Silicon dioxide (Microcrystalline quartz, SiO2)

Jasper

Microcrystalline Quartz (SiO2)

Chert (Jasper)

Silicon dioxide (SiO2)