Inderite
Current inventory:  0 gems
 

  
Inderite is named for Inder Lake, Kazakhstan, near which the first specimens were collected.

Discovered in 1937;   IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

MgB₃O₃(OH)₅ · 5(H₂O)

Hydrated Magnesium Borate Hydroxide

Molecular Weight:

279.85 gm

Composition:

Magnesium

8.69 %

Mg

14.40 %

MgO

Boron

11.59 %

B

37.32 %

B₂O₃

Hydrogen

5.40 %

H

48.28 %

H₂O

Oxygen

74.32 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Borates

Strunz 8th Ed. ID:

5/H.06-20

Nickel-Strunz 10th Ed. ID:

6.CA.15

6 : BORATES
C : Triborates
A : Neso-triborates

Related to:

Inyoite Group. Kurnakovite - Solongoite Series. Dimorph of Kurnakovite.

Members of Group:

Inyoite Group: Inderborite, Inderite, Inyoite, Kurnakovite, Meyerhofferite, Solongoite

Varieties:

None

Synonyms:

Lesserite, Loesserite

Crystal Data

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

As long prismatic crystals with nearly square cross-section, to 30 cm; may be as aggregates of minute needles; reniform nodular, massive.

Twinning:

None

Physical Properties

Cleavage:

Perfect on {010}, Good on {110}

Fracture:

Irregular/Uneven

Tenacity:

Brittle

Moh's Hardness:

2.5 - 3.0

Density:

1.80 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Other:

Insoluble in water. Readily soluble in warm, dilute HCl.

Optical Properties

Color:

Colorless to White, Pink

Transparency:

Translucent to Transparent

Luster:

Vitreous to Pearly on cleavages, Dull, Greasy

Refractive Index:

1.488 - 1.505  Biaxial ( + )

Birefringence:

0.0170

Dispersion:

Weak; r > v

Pleochroism:

None

Occurances

Geological Setting:

Rarely as a primary mineral in lacustrine borate deposits.

Common Associations:

Hydroboracite (Inder deposit, Kazakhstan); Kurnakovite (Sarikaya, Turkey); Borax, Orpiment, Realgar, Ulexite (Boron, California, USA)

Common Impurities:

None

Type Locality:

Deposit No. 7, Kzyl Tau Mt, Inder B deposit and salt dome, Atyrau (Gur'yev), Atyrau Oblysy (Atyrau Oblast'), Kazakhstan

Year Discovered:

1937

View mineral photos:

Inderite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Inderite, also known as Lesserite, is a relatively rare borate mineral but extremely rare as a faceted gem. It is very soft and difficult to cut because of its softness and perfect cleavage. Inderite is formed in Borate deposits in arid regions.

There are very few locations where Inderite can be found but only one source for gem quality crystals which is Boron, Kramer District, Kern County, California, USA.
 

  
Inderite gems for sale:

We have not photographed our Inderite gems. Please check back soon.