Danburite Value, Price, and Jewelry Information


danburite - crystals
“Danburite,” Charcas, Mun. de Charcas, San Luis Potosí, Mexico. © Rob Lavinsky, www.iRocks.com. Used with permission.

A hard and durable gemstone, danburite is an excellent choice for jewelry wear. Although the mineral isn't rare, large facetable pieces are scarce. Still, sufficient material exists for gem enthusiasts and adventurous jewelry lovers to add this lovely and under appreciated stone to their collections.

Danburite Value

Tried and true gem value factors apply to danburite. All other things being equal, larger, cleaner, better cut and better colored stones have a higher value per carat. However, a truly colorless specimen would surpass a very pale yellow or slightly pink stone in value per carat.

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Danburite Value via Gem Price Guide

Danburite Information

DataValue
NameDanburite
Crystallography Orthorhombic; Crystals prismatic with wedge-shaped terminations, like topaz.
Refractive Index 1.627 - 1.641
Colors Colorless, white, pink, light to dark yellow, yellowish brown, brown.
Luster Vitreous to greasy.
Fracture Fracture subconchoidal to uneven. Brittle.
Hardness 7
Specific Gravity 2.97-3.03, usually 3.00.
Birefringence 0.006-0.008
Cleavage Indistinct
Dispersion 0.017
Luminescence Sky blue to bright blue-green in LW. Also, thermoluminescent (red).
Spectral Sometimes shows rare earth spectrum, so-called didymium lines.
Wearability Excellent
Enhancements None Known
Transparency Trasparent
FormulaCaB2Si2O8
Pleochroism None
Optics a = 1.630-1.633; β = 1.633-1.637; γ = 1.636-1.641. Biaxial (-); 2V= 88° in red to green light; optically (+) at lower wavelengths.
EtymologyAfter the type locality, Danbury, Connecticut.
OccurrenceIn dolomites; in carbonate veins in granitic rocks.
Inclusions Fingerprints (healed fractures), hollow growth tubes.
danburite - Charcas Mexico
Danburite: Charcas, Mexico (8.5, crystal ~ 2 1⁄2 inches long). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Comments

Danburite’s colors range from colorless to light yellow or pale pink to tan. With poor cleavage and a hardness of seven, it catches popular jewelry stones such as quartz and topaz in toughness. Although its modest dispersion means cut danburites lack fire, properly cut gems are very bright.

Identifying Characteristics

Interestingly, most specimens fluoresce a sky blue color in longwave ultraviolet light and phosphoresce red when heated.

danburite - type locality
“Danburite from Type Locality,” mass with crude crystal faces, Danbury, Fairfield Co., Connecticut, USA. © Rob Lavinsky, www.iRocks.com. Used with permission.

Synthetics

No known enhancements, synthetics, or imitations on the market.

Sources

First discovered in Danbury, Connecticut, danburite has been found and mined in Japan, Madagascar, Mexico, and Myanmar. Notable locations include:

  • United States: Danbury, Connecticut, type locality.
  • Japan: Obira, Bungo, Kyushu, colorless crystals, sometimes gemmy.
  • Madagascar: yellow crystals at Mt. Bity, often gemmy.
  • Mexico: Charcas, San Luis Potosí, colorless, yellow, light pink (gemmy).
  • Myanmar: Mogok, yellow and colorless, sometimes large crystals (rolled pebbles).
  • Russia: colorless, gemmy material.
  • Bolivia; China; Tanzania.
danburite - Myanmar
“Danburite,” Sakangyi, Mogok Township, Mandalay Division, Myanmar. © Rob Lavinsky, www.iRocks.com. Used with permission.

Stones Sizes

Danburites, especially colorless material from Mexico, typically range in size between 1 and 5 carats. Yellow gems from Myanmar between 7 and 10 carats are very rare today.

  • British Museum of Natural History (London): Myanmar, wine-yellow, step-cut, flawless, 135.61.
  • Smithsonian Institution (Washington, D.C): 18.4 (Myanmar, yellow) 12.4; 10.5 (Mexico, colorless); 7.9 (Japan, colorless).
  • Los Angeles County Museum (Los Angeles): Madagascar, brownish, emerald cut, 115.
  • Royal Ontario Museum (Toronto, Canada): Russia, colorless, step-cut, 12.72.
  • Private Collections: 20 (Myanmar, peach color); 22.76 (Madagascar, yellow); 37 (Russia).
danburite - tanzania
“Danburite,” Merelani Hills, Arusha Region, Tanzania. © Rob Lavinsky, www.iRocks.com. Used with permission.

Care

Due to some heat sensitivity, avoid steam cleaning this gem. Otherwise, danburite requires no special care. You can use these gems for all jewelry applications, including rings and bracelets. Consult our gemstone jewelry cleaning guide for more care recommendations.

danburite - cut
“Cut Danburite,” Locality: Anjanabonoina, Ikaka, Ambohimanambola Commune, Betafo District, Vakinankaratra Region Antananarivo Province, Madagascar (0.47 cts), by Didier Descouens. Licensed under CC By-SA 4.0.