Beryllonite Value, Price, and Jewelry Information

Cushion-cut beryllonite, 4.82 cts, 12.3 x 8.4 x 6.2 mm, Brazil. © ARK Rare Gems. Used with permission.

Beryllonite

Difficult to facet and typically colorless, beryllonite is a rare collector’s gem. Some specimens can show a striking cat’s eye.

Beryllonite Information

Data Value
Name Beryllonite
Crystallography Monoclinic. Crystals tabular or prismatic, usually etched. Twinning common. May be pseudo-orthorhombic.
Refractive Index 1.552-1.561
Colors Colorless, white, pale yellow.
Luster Vitreous; pearly on cleavage.
Hardness 5.5-6
Fracture Conchoidal
Specific Gravity 2.84 (pure); usually 2.80-2.85.
Birefringence 0.009
Cleavage Perfect 1 direction, good 1 direction
Dispersion 0.010
Luminescence None
Luminescence Present No
Transparency Transparent to opaque
Absorption Spectrum Not diagnostic
Phenomena Chatoyancy
Formula NaBePO4
Pleochroism None
Optics α = 1.552; β = 1.558; γ = 1.561. Biaxial (-), 2V = 68°.
Optic Sign Biaxial -
Etymology Named after the beryllium in its composition.
Occurrence Granite pegmatites.
Inclusions Hollow canals and fluid cavities arranged parallel to crystal axis. Material from Stoneham, Maine has tubes, gas bubbles and acicular crystals.
beryllonite rough and cut set - Maine

Beryllonite: Maine (gem: ~ 2 cts, rough: 1” across). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Comments

Beryllonites aren’t really suited for jewelry use. With both perfect and good directions of cleavage, they’re difficult to cut. Typically colorless or pale yellow and with little dispersion, their low refractive index also means they lack brilliance. Their hardness falls below the mark that would make them durable enough for everyday wear.

Nevertheless, beryllonite’s rarity makes any crystal a valued specimen for a collector, and faceted pieces are especially prized. Long known only from Maine, a few new sources have been discovered but haven’t yielded too much facetable material. However, beryllonites from Afghanistan can sometimes show chatoyancy when cabbed properly. This cat’s eye effect is caused by the formation of inclusions of parallel tubes.

cat's eye beryllonite - Afghanistan

Cat’s eye beryllonite, oval cabochon, 1.26 cts, 10 x 6 mm, Afghanistan. © The Gem Trader. Used with permission.

Please note, despite its name, beryllonite doesn’t belong to the beryl species. Although both contain the rare element beryllium, these gems have different chemical formulas and crystal systems.

Synthetics

Scientists have synthesized beryllonites, and while they may seem unlikely choices, synthetic beryllonites have indeed appeared in jewelry. 

Enhancements

No known gemstone treatments or enhancements.

Sources

Stoneham, Maine, the type locality, produces cuttable crystals as well as crystalline masses up to 1-2 inches. However, only small, clean areas within such masses could be cut.

Newry, Maine produces opaque white crystals, not really cuttable.

Other notable sources of gem-quality material include the following:

  • Afghanistan, Brazil, Pakistan.
beryllonite crystal - Pakistan

Beryllonite crystal specimen, 46 g, 58 x 42 x 15 mm, Skardu, Pakistan. Photo courtesy of liveauctioneers.com and Jasper52.

Stone Sizes

Usually only available as small, colorless stones, most gems weigh less than 5 carats. Stones up to 10 carats have been cut, but their clarity isn’t clean. As a mineral, beryllonite is rare and very few gems are known.

All the gems listed below came from Maine.

  • Smithsonian Institution (Washington, DC): 2.5, 3.3, 3.9, 5.10.
  • Devonian Group (Calgary, Alberta, Canada): 5.70.
  • Harvard University: 6.22.
  • Private Collection: 7.82, 8.77, 4.32.
faceted beryllonite - Maine

One of the world’s largest beryllonite gems, 20.64 cts, from Stoneham, Maine. Photo © Joel E. Arem, PhD, FGA. Used with permission.

Care

Since beryllonites may contain liquid inclusions, don’t use mechanical systems to clean them. Use only water, mild detergent, and a soft brush. Avoid any cleaner that contains acid, since these gems are soluble in acid.

Use protective settings for beryllonites, especially for ring use, or reserve them for occasional wear.

For more care recommendations, consult our gemstone jewelry cleaning guide.

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