Gems by Rarity

Gemstone types grouped by geological rarity

Singular Occurrence

Gem Type Description
Afghanite Rare blue sodium, potassium, calcium tectosilicate; primarily known from Afghanistan with very limited gem material.
Alexandrite Color-change chrysoberyl that forms under very specific conditions; collector-grade examples are rare.
Benitoite Blue barium titanium silicate first discovered in California; gem-quality specimens are localized and rare.
Bixbite Very rare red beryl with extremely limited occurrences (notably in Utah); collector-grade material is scarce.
Black Opal Opal with dark body tone and vivid play of color; primarily from Lightning Ridge, Australia.
Blue Diamond Extremely rare fancy color diamond; blue color from boron. Hope Diamond (45ct) most famous example. Among most valuable gems per carat.
Charoite Purple silicate from Russia only; distinctive swirling patterns.
Clinohumite Orange to brownish-orange magnesium silicate; gem-quality material is exceptionally rare, primarily from Tajikistan.
Grandidierite A very rare blue-green mineral with limited localities; collector-grade gems are scarce.
Green Diamond Extremely rare fancy color diamond; natural green from radiation exposure over millions of years. Dresden Green (41ct) most famous example.
Jeremejevite Extremely rare aluminum borate mineral; facet-quality crystals are exceptionally scarce with very few sources worldwide.
Larimar Blue pectolite from Dominican Republic only; distinctive volcanic blue.
Moldavite Green tektite (natural glass) from meteorite impact in Czech Republic 15 million years ago. Not a true mineral; impact glass.
Musgravite Among the rarest gemstones; found in tiny quantities and valued by collectors.
Painite Once among the rarest minerals known, with very few gem-quality crystals; exceptionally scarce.
Paraiba Tourmaline Copper-bearing tourmaline with vivid neon blue-green color; original Brazilian deposits are nearly depleted, making it exceptionally rare.
Pezzottaite Cesium-rich beryl variety discovered in Madagascar 2002. Deep raspberry pink color. Named after Italian mineralogist Federico Pezzotta.
Phosphophyllite Zinc iron phosphate; exceptional blue-green color. Extremely soft and perfect cleavage makes it one of most fragile gems.
Pink Diamond Extremely rare fancy color diamond; Argyle mine closure (2020) has made supply even more limited. Among the most valuable gemstones per carat.
Poudretteite Extremely rare potassium sodium boron silicate. Discovered in Quebec 1960s; gem-quality from Myanmar. Soft pink to raspberry color.
Serendibite Exceptionally rare mineral with very few known gem specimens; highly prized by specialists.
Sugilite Purple manganese silicate; primarily from South Africa.
Taaffeite Extremely rare gem originally mistaken for spinel; fine material is exceptionally scarce.
Tanzanite Violet-blue zoisite found only in a small area near Mount Kilimanjaro (Tanzania); limited primary source.
Vayrynenite Extremely rare manganese beryllium phosphate; one of the rarest minerals with only a handful of known specimens.

Unique Geological

Gem Type Description
Axinite Calcium aluminum borosilicate; distinctive wedge-shaped crystals. Cinnamon-brown to violet colors; strong pleochroism.
Black Diamond Polycrystalline diamond with dark color from graphite inclusions or irradiation; natural Carbonado from Brazil and Central African Republic is rarest form.
Blue Spinel Blue spinel colored by iron or cobalt; fine cobalt blue material is exceptionally rare and valuable.
Brazilianite Sodium aluminum phosphate; chartreuse yellow-green color. Named after Brazil; relatively rare phosphate gem.
Burmese Spinel Fine spinel from Myanmar's Mogok region; red, pink, and blue varieties most valued.
Cat's Eye Chrysoberyl Chrysoberyl with chatoyancy; fine cat's eyes with sharp, centered bands are valuable.
Cerussite Lead carbonate with exceptional adamantine luster and high dispersion. Extremely soft and brittle; collector cuts only.
Chondrodite Magnesium silicate hydroxide/fluoride; orange to reddish-brown color. Humite group mineral; attractive warm colors; rare in gem quality.
Chrome Sphene Chrome-bearing titanite with intense green color. Higher dispersion than diamond. Soft but exceptionally brilliant; collector favorite.
Color-Change Garnet Garnet showing color change; pyrope-Spessartite hybrids most common.
Cuprite Copper oxide with adamantine luster; deep red color. Transparent crystals very rare; most material opaque. Too soft for jewelry.
Demantoid Green andradite garnet with exceptional dispersion; classic Russian deposits and newer African sources are limited.
Dioptase Copper cyclosilicate; vivid emerald-green color rivals emerald. Too soft for jewelry; primarily specimen interest.
Emerald Green beryl colored by chromium and/or vanadium; fine quality emeralds from classic localities (Colombia, Zambia) are geologically rare.
Euclase Beryllium aluminum silicate; exceptional blue color. Perfect cleavage makes cutting extremely difficult; rare in clean crystals.
Hackmanite Tenebrescent variety of sodalite that changes color when exposed to UV light. Purple fades to white in sunlight, then returns. Rare phenomenon.
Hambergite Beryllium borate hydroxide; colorless to white with exceptional brilliance. High dispersion creates fire; perfect cleavage makes cutting difficult.
Hauyne Rare sodium calcium aluminum silicate sulfate. Vivid electric blue color. Extremely rare in gem quality; most stones under 1 carat.
Herderite Calcium beryllium phosphate hydroxide/fluoride; colorless to pale yellow or green. Rare collector gem; often confused with other phosphates.
Imperial Topaz Orange to pink-orange topaz; finest material from Brazilian deposits is rare and represents the most valuable topaz variety.
Jadeite Sodium aluminum silicate; imperial green jadeite from Myanmar most valued.
Kornerupine Rare borosilicate mineral; gem-quality material is scarce.
Mahenge Spinel Vivid hot pink spinel from Mahenge region, Tanzania. Discovered 2007; neon-like pink color unique to this deposit. Highly prized by collectors.
Opaque Hauyne Opaque variety of hauyne with vivid blue color. Distinct from transparent hauyne in pricing and market. Primarily used for carvings and cabochons. Rarer than transparent material.
Padparadscha Sapphire Rare pink-orange sapphire; the classic color combination is found primarily in Sri Lanka and is geologically uncommon.
Parisite Rare earth calcium carbonate fluoride; golden-brown to yellowish color. Contains cerium and lanthanum; collector mineral with attractive color.
Phenakite Rare beryllium silicate; exceptionally clear crystals prized by collectors. Fine specimens from Russia, Brazil, and Madagascar.
Pollucite Cesium aluminum silicate; primary cesium ore. Colorless and transparent material rare; collector cuts only.
Red Spinel Pure red spinel rivaling ruby in color; fine specimens from classic localities (Burma, Tajikistan) are geologically rare.
Rhodochrosite Pink manganese carbonate; transparent facetable material is rare.
Ruby Gem-quality corundum with chromium — superb stones are limited to a handful of classic localities.
Sapphire Variety of corundum; fine-color sapphires are mined in select regions and are prized.
Sapphirine Rare magnesium aluminum oxide silicate; blue to greenish-blue color. Extremely rare in gem quality; most material opaque or translucent.
Sphalerite ve ry high dispersion but fragile; gem-quality sphalerite is rare and mainly for collectors.
Sphene Highly refractive titanite with dispersive fire; fine faceting material is rare.
Star Ruby Ruby with asterism; quality depends on star sharpness, centering, and body color.
Star Sapphire Sapphire with asterism; quality depends on star sharpness, centering, and body color.
Stibiotantalite Antimony tantalum oxide; yellowish-brown to reddish-brown color. Extremely rare tantalum mineral; high refractive index creates adamantine luster.
Tsavorite Bright green grossular garnet colored by vanadium and/or chromium; found primarily in East Africa and is geologically rare.
Uvarovite Emerald green garnet; rarely found in facetable sizes, usually as druzy.
Yellow Diamond Fancy color diamond with yellow color from nitrogen; most common fancy color diamond. Vivid and intense yellows most valuable.

Limited Occurrence

Gem Type Description
Achroite Colorless tourmaline variety; rare compared to colored tourmalines. Name from Greek "achros" (colorless).
Albite Sodium feldspar; peristerite variety shows blue sheen. Cleavelandite variety forms bladed crystals.
Amazonite Green to blue-green microcline feldspar; popular ornamental stone.
Amblygonite Lithium aluminum phosphate; colorless to pale yellow. Perfect cleavage makes cutting challenging.
Ametrine Natural bicolor quartz showing amethyst purple and citrine yellow; primarily from Bolivia.
Andalusite Noted for strong pleochroism; gem-quality stones are limited in supply.
Andesine Plagioclase feldspar; red varieties from Tibet/China controversial due to treatment concerns.
Andradite Calcium-iron garnet; most varieties are uncommon with demantoid being the most valued.
Apatite Calcium phosphate; neon blue and green varieties most valued.
Aquamarine Blue beryl colored by iron; larger sizes and deeper saturation increase value.
Azurite Deep blue copper carbonate; often found with malachite.
Bastnasite Cerium rare-earth fluorocarbonate mineral. Yellow to reddish-brown. Important rare earth ore; primarily mineralogical interest.
Beryl Generic beryl entry for mixed or unspecified beryl varieties. Includes goshenite, morganite, heliodor, and other beryls. Hardness 7.5-8.
Blue Topaz Blue topaz colored by iron; most commercial blue topaz is irradiated. Swiss blue and London blue varieties most valued. Abundant supply from Brazil.
Boulder Opal Opal with ironstone matrix; primarily from Queensland, Australia.
Brown Diamond Fancy color diamond with brown color; marketed as champagne, cognac, or chocolate diamonds. Most affordable fancy color.
Bytownite Plagioclase feldspar; golden to champagne colors with aventurescence. Oregon material most valued.
Cassiterite Tin oxide mineral and primary tin ore. Brown to black with adamantine luster; high dispersion when transparent. Occasionally faceted.
Chrysoberyl Beryllium aluminum oxide mineral. Generic chrysoberyl entry for name matching priority. Includes alexandrite (color-change) and cat's eye (cymophane) varieties.
Chrysoprase Apple green chalcedony colored by nickel; fine color is less common.
Crystal Opal Transparent to translucent opal with play of color; body allows light transmission.
Danburite Calcium borosilicate mineral named after Danbury, Connecticut. Typically colorless to pale yellow; resembles topaz. Good brilliance and dispersion.
Diaspore Aluminum oxide hydroxide showing color change; gem-quality material is primarily from Turkey and relatively uncommon.
Diopside Calcium magnesium silicate; chrome diopside from Russia most valued.
Elbaite Lithium-rich tourmaline; most colorful tourmaline variety. Includes watermelon, rubellite, indicolite varieties.
Enstatite Magnesium silicate; gem-quality material is uncommon.
Epidote Calcium aluminum iron silicate; distinctive pistachio green color. Strong pleochroism; collector cuts.
Erythrite Cobalt arsenate mineral known as "cobalt bloom". Vivid crimson to pink color. Very soft; purely specimen interest.
Fire Opal Orange to red opal; Mexican material with play of color is most valued.
Goshenite Colorless beryl; historically used as diamond simulant but now primarily a collector gem.
Green Beryl Light green beryl that doesn't qualify as emerald; less saturated green color.
Grossular Calcium aluminum garnet; includes hessonite and other color varieties.
Hawk's Eye Blue-gray fibrous quartz with chatoyancy; less common than tiger's eye.
Heliodor Yellow to greenish-yellow beryl; available but less popular than other beryl varieties.
Hiddenite Green spodumene variety; gem-quality pieces are uncommon and prized by collectors.
Hyalite Colorless glassy opal; notable for strong green UV fluorescence.
Hypersthene Iron magnesium silicate with bronzy sheen; collector stone.
Idocrase Calcium magnesium aluminum silicate; also known as vesuvianite. Green californite variety most valued; yellow-brown common; jade-like appearance.
Indicolite Blue tourmaline; occurs less frequently than other tourmaline colors with quality material from limited sources.
Iolite Violet-blue cordierite with strong pleochroism; popular sapphire alternative.
Jelly Opal Translucent opal with little or no play of color; gelatinous appearance.
Kunzite Pink to violet spodumene that requires careful handling; commercial gem material is sourced from limited deposits.
Kyanite Blue aluminum silicate with variable hardness; challenging to cut.
Labradorite Feldspar with labradorescence; spectrolite from Finland shows exceptional play of color.
Lapis Lazuli Blue rock composed mainly of lazurite; Afghan material most valued.
Malaya Garnet Pyrope-Spessartite garnet originally from Tanzania/Kenya border. Peachy-pink to reddish-orange colors. Name from Swahili for "outcast".
Mali Garnet Grossular-andradite hybrid from Mali; attractive yellow-green color.
Moonstone Feldspar with adularescence; fine blue sheen specimens are less common than white moonstone.
Morganite Pink beryl; gem material is reasonably available, but fine saturated colors are less common.
Nephrite Calcium magnesium silicate; mutton fat white nephrite from Xinjiang valued.
Oligoclase Plagioclase feldspar; gem-quality material is uncommon and primarily for collectors.
Opal Hydrated silica mineraloid with play of color. Generic opal entry for name matching priority. Includes precious and common opal varieties.
Opaque Emerald Opaque green beryl lacking the transparency and clarity of gem emerald. Distinct pricing from transparent emerald due to different market and applications. Used for carvings and cabochons.
Orthoclase Yellow feldspar; gem-quality material primarily from Madagascar.
Pargasite Calcium-sodium magnesium aluminum silicate hydroxide; amphibole mineral. Chrome-green variety most valued; strong pleochroism.
Peridot Green olivine; fine saturated colors from Myanmar, Pakistan, or Arizona are valued.
Peruvian Opal Blue to blue-green common opal from Peru; no play of color.
Petalite Lithium aluminum silicate; colorless to pale pink. Perfect cleavage makes cutting challenging; collector gem.
Pink Spinel Pink spinel occurs with moderate frequency; commercial material is available though top-color stones are less common.
Pink Topaz Natural pink topaz is uncommon; most pink topaz is heat-treated or represents the pink end of imperial topaz color range.
Prasiolite Green quartz; most is heat-treated amethyst, natural material rare.
Prehnite Green calcium aluminum silicate; attractive translucent green.
Pyrope Blood red garnet; fine color specimens are less common than almandine.
Rhodolite Pink to purple-red garnet; popular for its attractive color and durability.
Rhodonite Pink manganese silicate; often with black manganese oxide veins.
Rubellite Red to pink tourmaline that retains color in all lighting; fine saturated colors are uncommon.
Rutilated Quartz Quartz with rutile needle inclusions; golden and red rutile most valued.
Scapolite Sodium calcium aluminum silicate; yellow and purple varieties most valued.
Scheelite Calcium tungstate mineral with strong fluorescence under UV. Colorless to orange-brown. Primary tungsten ore; occasionally faceted.
Seraphinite Green clinochlore with silvery feathery patterns; ornamental use only.
Sillimanite Aluminum silicate polymorph; fibrous structure creates cat's eye effect. Violet-blue variety most valued.
Smithsonite Zinc carbonate in various colors; blue-green most valued. Soft but attractive; primarily cabochon use.
Spessartite Orange garnet; mandarin Spessartite from Nigeria highly valued.
Spinel Magnesium aluminum oxide mineral. Generic spinel entry for name matching priority. Historically confused with ruby; now recognized as valuable in its own right.
Spodumene Lithium aluminum silicate mineral. Generic spodumene entry; includes kunzite (pink) and hiddenite (green) varieties. Good brilliance but perfect cleavage requires care.
Sunstone Feldspar with aventurescence; Oregon sunstone with copper inclusions is most valued.
Tantalite Iron-manganese tantalate mineral and primary ore of tantalum. Black to brownish-black with submetallic luster. Primarily collector and specimen interest.
Tanzanian Spinel Spinel from Tanzania including famous Mahenge deposit; hot pink highly valued.
Tourmalinated Quartz Quartz with black tourmaline needle inclusions; graphic patterns valued.
Triplite Sodium calcium aluminum silicate; includes blue and pink varieties. Strong pleochroism; collector cuts.
Turquoise Blue-green copper aluminum phosphate; Persian and American material valued.
Verdelite Green tourmaline variety; ranges from yellow-green to deep forest green. Chrome verdelite (colored by chromium) is rarer and more valuable.
Vesuvianite Calcium aluminum silicate; also called idocrase. Green californite variety most valued; yellow-brown common.
Vietnamese Purple Spinel Rare purple-colored spinel variety from Vietnam; highly prized for its unique vibrant purple color. Limited availability makes it a sought-after collector's gem.
Watermelon Tourmaline Tourmaline with pink center and green rim; natural color zoning is attractive but less common than single-color varieties.
White Opal Light-bodied opal with play of color; most common precious opal variety.
Xenotime Yttrium phosphate mineral containing rare earth elements. Brown to yellowish-brown with vitreous luster. Collector mineral.
Zircon Natural zircon with high dispersion; blue heat-treated Cambodia material popular.
Zoisite Calcium aluminum silicate; includes tanzanite (blue variety) and thulite (pink variety). Generic zoisite typically green.

Abundant Minerals

Gem Type Description
Agate Banded chalcedony; numerous varieties with different patterns and colors.
Almandine Deep red garnet; most common garnet variety.
Amethyst Purple quartz; abundant but fine deep purple material is less common.
Aragonite Calcium carbonate polymorph; forms prismatic crystals and stalactitic masses. Too soft for jewelry wear; primarily collector specimens.
Aventurine Quartz with mica or fuchsite inclusions creating sparkle; green most common.
Bloodstone Dark green chalcedony with red jasper spots; traditional birthstone.
Calcite Calcium carbonate with perfect cleavage; strong birefringence. Optical calcite (Iceland spar) valued for double refraction.
Carnelian Orange to red-orange chalcedony; historically valued, now common.
Chalcedony Cryptocrystalline quartz; includes many varieties like agate and carnelian.
Citrine Yellow to orange quartz; most commercial citrine is heat-treated amethyst.
Diamond While individual high-quality large diamonds are rare, diamond deposits worldwide are numerous and commercial production is substantial.
Feldspar Generic feldspar entry for mixed or unspecified feldspar varieties. Includes moonstone, sunstone, labradorite, and other feldspars. Hardness varies by variety.
Fluorite Calcium fluoride in many colors; too soft for jewelry wear.
Hematite Iron oxide with metallic luster; black to steel-gray with red streak. Often used for intaglios and seals.
Jasper Opaque cryptocrystalline quartz; numerous varieties with different patterns.
Malachite Banded green copper carbonate; popular ornamental stone.
Milky Quartz White translucent quartz; very common and of minimal gem value.
Onyx Black and white banded chalcedony; solid black onyx is usually dyed agate.
Quartz Silicon dioxide; includes many varieties. Generic quartz entry for name matching priority.
Rock Crystal Colorless transparent quartz; historically valued but now common.
Rose Quartz Pink quartz; rarely transparent, usually translucent to opaque.
Sardonyx Red-brown and white banded chalcedony; historically used for cameos.
Serpentine Magnesium silicate group; includes bowenite and antigorite. Often used as jade substitute. Soft and variable hardness.
Smoky Quartz Brown to black quartz; natural and irradiated material available.
Sodalite Blue sodium aluminum silicate; lapis lazuli alternative.
Synthetic Emerald Lab-created corundum (Al2O3) with same physical and chemical properties as natural sapphire. Various colors produced.
Synthetic Ruby Lab-created corundum (Al2O3) with same physical and chemical properties as natural sapphire. Various colors produced.
Synthetic Sapphire Lab-created corundum (Al2O3) with same physical and chemical properties as natural sapphire. Various colors produced.
Tiger's Eye Fibrous quartz with chatoyancy; golden brown most common, red and blue available.

Common Gemstones

Gem Type Description
Garnet Silicate mineral group with many species. Generic garnet entry for name matching priority. Includes almandine, pyrope, Spessartite, grossular, andradite, and uvarovite.
Topaz Aluminum silicate mineral. Generic topaz entry for name matching priority. Blue topaz very common (treated); imperial topaz (orange-pink) is rare and valuable.
Tourmaline Boron silicate mineral group with many color varieties. Generic tourmaline entry for name matching priority. Includes rubellite, indicolite, verdelite, and more.

Abudant Minerals

Gem Type Description
Ammolite
Lepidolite