Gemology Encyclopedia

Rare & Exceptional Gemstones

A curated selection of the world's rarest gem species — from collector-grade rarities to legendary stones of extraordinary scarcity, with rarity scores of 7 or above.

Entries 44
Tiers 4
44 gems
Legendary Alexandrite

Fine alexandrite with strong color change is exceptionally rare.

Legendary Benitoite

Benitoite is extremely rare as a facetable gem and closely associated with California.

Legendary Musgravite

Musgravite is one of the rarest facetable gemstones.

Legendary Painite

Painite is one of the most famous ultra-rare collector minerals.

Legendary Paraiba Tourmaline

Paraiba tourmaline is exceptionally rare, especially vivid copper-bearing neon blue material.

Legendary Pink Diamond

Natural pink diamonds are among the rarest and most valuable gems; supply has been severely restricted since the closure of the Argyle mine in 2020.

Legendary Poudretteite

Poudretteite is an exceptionally rare collector gemstone.

Legendary Red Beryl

Red beryl is one of the rarest beryl varieties and is usually found in small sizes.

Legendary Serendibite

Gem-quality serendibite is exceptionally rare.

Legendary Taaffeite

Taaffeite is an exceptionally rare faceted collector gem.

Collector Grade Black Opal

Fine black opal is among the rarest and most valuable opal types.

Collector Grade Cobalt Blue Spinel

Fine cobalt-blue spinel is among the rarest gem-quality spinels, commanding prices rivaling fine sapphire.

Collector Grade Color Change Garnet

Color change garnet is one of the rarest garnet categories, especially with strong color shift.

Collector Grade Grandidierite

Fine transparent grandidierite is extremely rare.

Collector Grade Ha├╝yne

Ha├╝yne is exceptionally rare in faceted form; top blue material from the Eifel region of Germany is virtually unobtainable commercially.

Collector Grade Jadeite

Fine imperial jadeite is extremely rare and highly valued.

Collector Grade Jeremejevite

Gem-quality jeremejevite is extremely rare and mostly collected by specialists.

Collector Grade Padparadscha Sapphire

Padparadscha sapphire is one of the rarest sapphire color varieties, especially untreated balanced pink-orange stones.

Collector Grade Sinhalite

Sinhalite is extremely rare in faceted form; most known faceted specimens are of museum or advanced collector quality.

Extremely Rare CatÔÇÖs Eye Chrysoberyl

Fine chrysoberyl catÔÇÖs eye with sharp chatoyancy and good color is very rare.

Extremely Rare Color Change Sapphire

Color change sapphire is rare, especially with a strong and attractive color shift.

Extremely Rare Demantoid

Demantoid is rare, and classic Russian stones with horsetail inclusions command strong collector interest.

Extremely Rare Emerald

Emerald is commercially available, but vivid stones with high clarity and minor treatment are very rare.

Extremely Rare Imperial Topaz

Imperial topaz is rare, especially fine untreated reddish-orange to pinkish-orange stones.

Extremely Rare Maxixe Beryl

Maxixe-type blue beryl is rare and often unstable in color, making durable gem material uncommon.

Extremely Rare Orange Spinel

Clean, vividly saturated orange spinel is rare; most material is brownish or muted in tone.

Extremely Rare Red Spinel

Fine vivid red spinel rivaling ruby is very rare and highly valued by collectors.

Extremely Rare Ruby

Ruby is commercially available, but fine untreated vivid red ruby is very rare.

Extremely Rare Zultanite

Zultanite-quality color-change diaspore is rare and source-limited.

Very Rare Blue Sapphire

Blue sapphire is common in commerce, but fine untreated vivid blue stones, especially top origins, are very rare.

Very Rare Boulder Opal

Fine boulder opal with strong play-of-color is rare.

Very Rare Chrome Tourmaline

Chrome tourmaline is rare and valued for saturated green color.

Very Rare Fancy Yellow Diamond

Natural vivid yellow diamonds are rare; lighter yellow stones treated for color are more common in the market.

Very Rare Hiddenite

True hiddenite is rare compared with kunzite and other spodumene varieties.

Very Rare Kornerupine

Fine gem kornerupine is rare and mostly seen in specialist collections.

Very Rare Liddicoatite

Liddicoatite is the calcium-dominant tourmaline species; well-formed faceted gems are uncommon and primarily of interest to collectors.

Very Rare Pink Spinel

Vivid hot-pink and neon-pink spinel, especially from Mahenge, is increasingly rare and collector-prized.

Very Rare Purple Spinel

Pure vivid purple spinel is uncommon; most material trends toward grayish or brownish purple.

Very Rare Red Zircon

Fine red zircon is much rarer than blue or brown zircon.

Very Rare Sapphire

Sapphire is widely traded, but fine untreated stones and rare phenomena/colors are much scarcer.

Very Rare Star Ruby

Well-defined, sharp six-rayed star in a fine red stone is increasingly rare.

Very Rare Star Sapphire

Star sapphire is uncommon, and stones with sharp stars, good transparency and attractive color are very rare.

Very Rare Tanzanite

Tanzanite is geographically restricted and fine saturated blue-violet stones are rare.

Very Rare Tsavorite

Tsavorite is rare, especially vivid green stones above two carats.