Boracite Value, Price, and Jewelry Information

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Light bluish green boracite, 0.33 cts, 4.3 mm, square cut, Lower Saxony, Germany. © The Gem Trader. Used with permission.

With light blue and green colors, no cleavage, and high hardness, boracite is an uncommon mineral. Unfortunately for jewelry lovers, faceted boracites are very rare.

Boracite Information

Data	Value
Name	Boracite
Crystallography	Orthorhombic. Pseudo-tetragonal. Crystals small and equant.
Refractive Index	1.658-1.673
Colors	Colorless, white, gray, orange, yellow, pale to dark green, bluish green, pink (very rare).
Luster	Vitreous.
Hardness	7-7.5.
Wearability	Good
Fracture	Conchoidal to uneven
Specific Gravity	2.95
Birefringence	0.010-0.011
Cleavage	None
Dispersion	0.024
Luminescence	Weak greenish (SW)
Luminescence Present	Yes
Luminescence Type	Fluorescent, UV-Short
Transparency	Translucent to transparent.
Absorption Spectrum	Not diagnostic.
Formula	Mg₃B₇O₁₃Cl
Pleochroism	None.
Optics	α = 1.658-1.662; β = 1.662-1.667; γ = 1.668-1.673. Biaxial (+), 2V =82°.
Optic Sign	Biaxial +
Etymology	Named after the boron in its composition.
Occurrence	Secondary deposits formed in evaporite sequences (seawater).

Boracite, Kalkberg Hill, Luneburg, Lower Saxony, Germany, (type locality). © Rob Lavinsky, www.iRocks.com. Used with permission.

Aqua-colored boracites, crystals about 2 mm across, specimen 5.8 x 3.2 x 1.8 cm. Boulby Mine, Loftus, North Yorkshire, England, UK. © Rob Lavinsky, www.iRocks.com. Used with permission.

Comments

Boracite forms in salt deposits and similar environments as a result of seawater evaporation in enclosed basins. Rare cut boracites can show delicate shades of blue, green, yellow, white, and grey and have moderate dispersion. Some stones are colorless.

Boracite, 0.21 cts. Photo © Joel E. Arem, PhD, FGA. Used with permission.

Identifying Characteristics

Under physical pressure, boracite generates an electric charge. This is known as known the piezoelectric effect. This mineral also exhibits the pyroelectric effect. It generates an electric charge when heated.

Boracites decompose slowly in water.

Synthetics

Scientists have synthesized boracites for various purposes, including research into its electrical properties as well as radioactive waste storage. However, there’s no known jewelry use for this synthetic material.

Sources

Cuttable crystals occur only in the Stassfurt and Hanover districts of Germany, which usually yield small, pale crystals.

Other notable gem sources include the following:

United States: Otis, California; Choctaw Salt Dome, Louisiana.
England: North Yorkshire, Aislaby.
Bolivia; Canada; China; France; Kazahkstan.

This boracites on matrix specimen contains pale blue-gray crystals as well as a single, rare orange-pink crystal. Alto Chapare District, Chapare Province, Cochabamba Department, Bolivia. © Rob Lavinsky, www.iRocks.com. Used with permission.

Stone Sizes

Boracite crystals are very small and usually yield gemstones ranging from 1-2 carats, so gems over 2 carats would be considered extreme rarities.

Care

Although boracites react to water very slowly, keep them dry in storage, where they would otherwise have time to sit and decompose. Alcohol may be used in lieu of water for cleaning. Otherwise, since these stones have high hardness (7-7.5) and no cleavage, they require no special care. Consult our gemstone jewelry cleaning guide for more recommendations.