Stibiotantalite

Last updated
Stibiotantalite
Stibiotantalite-ch10a.jpg
General
Category Oxide minerals
Formula SbTaO4
IMA symbol Sttl [1]
Strunz classification 04.DE.30
Dana classification 08.01.06.02
Crystal system orthorhombic
Space group mm2
Unit cell a = 4.9, b = 11.79, c = 5.57Å, Z = 4; V = 321.78
Identification
Formula mass 336.70
Colouryellow to dark brown, reddish
Fracture brittle-conchoidal
Mohs scale hardness5.5
Streak light yellow
Diaphaneity transparent to translucent
Density 6 to 7.57
Refractive index 1.55 - 1.69
Birefringence Biaxial (+), a=2.3742, b=2.4039
2V angle 75.083
Dispersion strong

Stibiotantalite is a tantalate mineral found in complex granite pegmatites. [2] Stibiotantalite constitutes the tantalum endpoint of a Sb(Ta,Nb)O4 solid solution series with its niobium analogue stibiocolumbite. [3]

Contents

It is translucent to transparent, medium hard (5.5 mohs), appears yellow to dark brown, reddish or greenish brown, with an adamantine luster.

Stibiotantalite is found in veins and walls associated with tin mines. It is a fairly rare to rare mineral. Due to its relative softness, it is more likely to be found in mineral collections than in jewelry. [3]

Occurrence

Stibiotantalite has been found in several countries, but the most significant are Mozambique, Sri Lanka, and the USA. It occurs in complex granite pegmatites. [4]

Mozambique and the USA have the most localities where Stibiotantalite has been found. [5] Mozambique has 6, while the USA has 18. California alone has 15 of these localities.

Use

Stibiotantalite is primarily used as a gemstone. [4] These gems are vivid, shiny, and golden-brown. These gems come between 0.73 carats and 6.34 carats, with the average being 3.54. These gems are similar in appearance to sphalerite, but they are brown instead of orange. While stibiotantalite and tantalite are similar, stibiotantalite is softer, brighter, and heavier.

Etymology

The "stibio-" prefix is a reference to its antimony content. The tantalite suffix shows that the mineral is actually very similar to tantalite. [4]

References

  1. ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.
  2. ↑ "Stibiotantalite Mineral Data". Web Mineral. Retrieved March 9, 2019.
  3. 1 2 "Stibiotantalite Value, Price, and Jewelry Information". International Gem Society. Retrieved March 9, 2019.
  4. 1 2 3 "Stibiotantalite". Gemdat. Retrieved 28 September 2022.
  5. ↑ "Stibiotantalite". Mindat. Retrieved 28 September 2022.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.