Takovite
Current inventory: 0 gems
 

  
Takovite is named after Takovo, Gornji Milanovac, Moravica District, Serbia where it was discovered.

Discovered in 1955; IMA status: Valid (IMA Approved 1977)

Chemistry

Chemical Formula:

Ni₆Al₂(CO₃OH)(OH)₁₆ • 4(H₂O)

Hydrated Nickel Aluminum Hydroxy-Carbonate

Molecular Weight:

799.54 gm

Composition:

Aluminum

6.75 %

Al

12.75 %

Al₂O₃

Nickel

44.04 %

Ni

56.05 %

NiO

Hydrogen

3.06 %

H

27.32 %

H₂O

Carbon

1.13 %

C

4.13 %

CO₂

Oxygen

45.02 %

O

100.00 %

100.25 %

= TOTAL OXIDE

Classification

Mineral Classification:

Carbonates

Strunz 8th Ed. ID:

5/E.03-50

Nickel-Strunz 10th Ed. ID:

5.DA.50

5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H₂O
A : With medium-sized cations

Related to:

Hydrotalcite Group.

Members of Group:

Hydrotalcite Group: Desautelsite, Droninoite, Hydrotalcite, Iowaite, Meixnerite, Pyroaurite, Pyroaurite-2H, Pyroaurite-3R, Reevesite, Stichtite, Takovite, Woodallite 

Varieties:

None

Synonyms:

Eardleyite, Eardleyite-Zn

Crystal Data

Crystallography:

Trigonal - Hexagonal Scalenohedral

Crystal Habit:

(by analogy to the Hydrotalcite Group). Microcrystalline, platy, to 1 μm; commonly in veinlets and massive. 

Twinning:

None

Physical Properties

Cleavage:

n/a

Fracture:

n/a

Tenacity:

Brittle

Moh's Hardness:

~2.0

Density:

2.80 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

Bluish green, yellowish green

Transparency:

Translucent to opaque

Luster:

n/a

Refractive Index:

1.600 - 1.602  Uniaxial ( - )

Birefringence:

0.001 - 0.002

Dispersion:

n/a

Pleochroism:

n/a

Occurances

Geological Setting:

In a karstitic bauxite at the contact of limestone and metamorphosed serpentinite (Takovo, Serbia); an alteration product of nickel sulfides (Western Australia).

Common Associations:

Gibbsite, Allophane (Takovo, Serbia); Glaukosphaerite, Népouite, Gaspéite, Paratacamite, Nickeloan Magnesite, Gypsum, (Kambalda, Australia).

Common Impurities:

None

Type Locality:

Takovo, Gornji Milanovac, Moravica District, Serbia

Year Discovered:

1955 (IMA redefined and approved 1977)

View mineral photos:

Takovite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Takovite is a rare nickel carbonate mineral that belongs to the Hydrotalcite Group of minerals that also includes Stichtite among others. Takovite crystals are very rare and very small (less than 1 mm) so faceted gems come from opaque to translucent massive material from Lavrion District Mines, Lavrion District, Attikí Prefecture, Greece as seen in the picture above. This material has a beautiful bluish-green to green color but is very soft, with a Moh's hardness of 2, and has a very low density.

Takovite was named for its discovery locality at Takovo, Gornji Milanovac, Moravica District, Serbia. It was discovered and named by Serbian geochemist Zoran J. Maksimović (1923- ) in 1955 and first described by him in 1957 in the Compte Rendu des Séances de la Société Serbe de Géologie (Minutes of Sessions of the Serbian Geological Society). Takovite was reinvestigated by mineralologists Dr. David L. Bish and Dr. George W. Brindley in 1977 on samples from the type locality and redefined and approved by the IMA.

Takovite distribution: from Takovo, Serbia. In the Blangvette West mine, Le Thoronet, Var, France. On Mueo, New Caledonia. In Western Australia, at the Carr Boyd Rocks nickel mine; the Agnew nickel deposit, north of Kalgoorlie; from Kambalda, 56 km south of Kalgoorlie; and the Dordie North nickel deposit. In the USA, at Wells Canyon, Oquirrh Mountains, Utah County, Utah, and at the Alpine mine, Clear Creek, San Benito County, California.
 

  
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