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Nambulite
Current inventory:  1 gem
 

Nambulite

Chemistry:  (Li;Na)Mn2+Si10O28(OH)2

Discovered in 1972;   IMA status: Approved
Nambulite is named after Professor Matsuo Nambu (1917 -) of Tohoko University, Japan, for his studies of manganese minerals.

 

Classification

   

   

Mineral Classification:

Silicates

Strunz 8th Ed. ID:

8/F.27-50

 

8 : Silicates
F : Inosilicates (chain and band) double chains [Si2O6]4-
27 : Rhodonite - Inesite series

 

 

Crystal Data

   

   

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

Crystals are prismatic to tabular crystals, to 8 mm; massive in veinlets.

 

 

Physical Properties

   

 

Cleavage:

[001] Perfect, [100] Distinct, [010] Distinct

Fracture:

n/a

Tenacity:

Brittle

Moh's Hardness:

6.5

Density:

3.51 (g/cm3)

Radioactivity:

Not Radioactive

 

 

Optical Properties

   

   

Color:

Reddish brown, orange-brown, reddish orange

Transparency:

Transparent, Translucent to Opaque

Luster:

Vitreous

Refractive Index:

1.707 - 1.730  Biaxial (+)

Birefringence:

0.023

Dispersion:

Weak

Pleochroism:

Slight

 

 

Occurances

   

   

Geological Setting:

In veinlets cutting braunite ores in chert (Funakozawa mine, Japan).

Type Locality:

Funakozawa mine, Kitakami Mts, Iwate Prefecture, Tohoku Region, Honshu Island, Japan

Year Discovered:

1972

View mineral photos:

Nambulite Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Nambulite is a very rare mineral first found at the Funakozawa Mine in the Kitakami Mountains of Japan and more recently found at the Kombat Mine near Tsumeb, Namibia. Most Nambulite is opaque, occasionally translucent, very rarely transparent and only available as cabochons. There is a completely transparent, flawless crystal reported from the Namibian material but this is in a private mineral collection and not available for faceting. If there were any transparent, faceted gems, they would be extremely rare and very valuable. Nambulite has a very beautiful, very intense orange-red color.
 

  
Nambulite gems for sale:

Nambulite-001

Gem:

Nambulite

Stock #:

NAMB-001

Weight:

1.6280 ct

Size (w x d):

7.95 x 6.16 x 3.26 mm

Shape:

Oval Cabochon

Color:

Orangish Red

Clarity:

Opaque

Origin:

Honshu Island, Japan

Treatment:

None (natural)

Price:

SOLD

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Nambulite-001

This very rare gem is from the Funakozawa mine on the Honshu Island, Japan.


 

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