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Kurnakovite
Current inventory:  0 gems
 

Chemistry:  MgB₃O₃(OH)₅·5(H₂O)

Discovered in 1940;   IMA status: Valid (pre-IMA; Grandfathered).
Kurnakovite is named to honor Professor Nikolai Semenovich Kurnakov (1860-1941), Russian mineralogist and chemist, Institute of General and Inorganic Chemistry, Moscow, Russia.

Classification

Mineral Classification:

Borates

Strunz 8th Ed. ID:

5/H.06-10

Nickel-Strunz 10th Ed. ID:

6.CA.20

6 : BORATES
C : Triborates
A : Neso-triborates

Related to:

Dimorph of Inderite

Crystal Data

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

Rough prismatic crystals, to 37 cm; typically in dense aggregates

Twinning:

Infrequent, on an unknown law

Physical Properties

Cleavage:

[110] Good, [001] Indistinct

Fracture:

Conchoidal

Tenacity:

Brittle

Hardness (Mohs):

2.5 - 3.0

Density:

1.847 - 1.862 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioacitve

Other:

Insoluble in water. Soluble in warm acids.

Optical Properties

Color:

Colorless, White

Transparency:

Transparent, Translucent

Luster:

Vitrious, Pearly

Refractive Index:

1.488 - 1.525  Biaxial ( - )

Birefringence:

0.027 - 0.034 (very high)

Dispersion:

Weak, r > v

Pleochroism:

None

Occurances

Geological Setting:

An uncommon mineral, typically in lake-bed borate deposits.

Common Associations:

Szaibélyite (Lake Inder, Kazakhstan)

Type Locality:

Deposit No. 33, Inder B deposit and salt dome, Atyrau (Gur'yev), Atyrau Oblysy (Atyrau Oblast'), Kazakhstan

Year Discovered:

1940

View mineral photos:

Kurnakovite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Kurnakovite is a rare borate mineral and a very rare gem which is difficult to cut due to cleavage and softness. It is similar to and a dimorph of Inderite. Both minerals are colorless and pretty uninteresting as gems except for their rarity. There are very few locations where Kurnakovite is found and only one location where crystals large enough for faceting have been found. Relatively large crystals have been found at the Kramer borate deposit, Boron, Kern County, California, USA.
 

  
Kurnakovite gems for sale:

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