“Hurlbutite,” 4 mm crystal pair on matrix, Chandlers Mill, Newport, NH. Photo courtesy of New Hampshire Mineral Species. Used with permission.
Hurlbutite is an extremely rare mineral. Minute, colorless faceted stones have been cut from fragments.
Hurlbutite Information
| Data | Value |
|---|---|
| Name | Hurlbutite |
| Formula | CaBe2(PO4)2. |
| Etymology | After Cornelius Hurlbut, well-known professor of mineralogy at Harvard University. |
| Occurrence | In pegmatite with muscovite, albite, and other minerals. |
| Colors | Colorless to greenish white; may be stained yellow. |
| Fracture | Conchoidal |
| Hardness | 6 |
| Cleavage | None |
| Crystallography | Monoclinic; crystals prismatic, chunky, with etched surfaces and striations. |
| Refractive Index | 1.595-1.604 |
| Birefringence | 0.009 |
| Luminescence | None reported. |
| Luminescence Present | No |
| Absorption Spectrum | Not diagnostic. |
| Pleochroism | None. |
| Optics | a = 1.595; β = 1.601; γ = 1.604. Biaxial (-). |
| Optic Sign | Biaxial - |
| Luster | Vitreous to greasy. |
| Specific Gravity | 2.88. |
| Transparency | Transparent to translucent. |
“Hurlbutite,” 3 cm crystal in pegmatite matrix, Chandlers Mill Mine, Newport, NH. Photo courtesy of New Hampshire Mineral Species. Used with permission.
Comments
To date, only hurlbutite from the type locality, Chandlers Mill, Newport, New Hampshire, has yielded clean, cuttable gem material. However, finding this seldom seen stone as a faceted gem would be quite unusual.
Strontiohurlbutite (SrBe2(PO4)2) is the strontium (Sr) analogue of the hurlbutite group. Hurlbutites are calcium (Ca) dominant. Both contain the rare element beryllium (Be).
Strontiohurlbutites have a light blue color, while hurlbutites range from white to greenish white.
Synthetics
In laboratories, scientists have created both hurlbutites and strontiohurlbutites for research purposes using a hydrothermal process. However, no jewelry use of these synthetics is known.
Enhancements
None known.
Sources
Gem-quality hurlbutites come from the Smith Mine, Chandlers Mill, Newport, New Hampshire.
Other sources include:
- United States: Maine, South Dakota.
- Czech Republic; Finland; Spain; Sweden; Zimbabwe.
Fujian Province, China produces strontiohurlbutite.
Stone Sizes
Faceted gems, transparent and colorless, all fall under one carat in size.
Care
You’re more likely to find hurlbutites, if at all, in comprehensive mineral collections than jewelry collections. With no cleavage and a hardness of 6, just below quartz, the small, transparent and colorless gems would make interesting conversation pieces if worn with care. (These conversations would likely dwell on their rarity). Consult our Gemstone Jewelry Cleaning Guide for more information.
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