Bustamite
Current inventory:  0 gems
 

  
Bustamite was named after its discoverer General Anastasio Bustamente (1780-1853) of Mexico. It was discovered in 1822 in Tetela de Ocampo, Hidalgo, Mexico.

Discovered in 1822;  IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

(Mn,Ca)₃Si₃O₉

Manganese Calcium Silicate

Molecular Weight:

381.92 gm

Composition:

Calcium

7.87 %

Ca

11.01 %

CaO

Manganese

32.37 %

Mn

41.79 %

MnO

Silicon

22.06 %

Si

47.20 %

SiO₂

Oxygen

37.70 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/F.18-40

Nickel-Strunz 10th Ed. ID:

9.DG.05

9 : SILICATES (Germanates)
D : Inosilicates
G : Inosilicates with 3-periodic single and multiple chains

Related to:

Wollastonite Group. The Mn analogue of Ferrobustamite.

Members of Group:

Wollastonite Group: Bustamite, Ferrobustamite, Pectolite, Serandite, Tanohataite, Wollastonite

Varieties:

None

Synonyms:

Buchstamite

Crystal Data

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

Crystals prismatic, needlelike, to 2.5 cm, or tabular; commonly fibrous, cleavable massive. Twinning: Composition plane, simple twins, uncommon.

Twinning:

None

Physical Properties

Cleavage:

Perfect on {100}, Good on {110} and {110}, Poor on {010}

Fracture:

Sub-Conchoidal

Tenacity:

Brittle

Moh's Hardness:

5.5 - 6.5

Density:

3.32 - 3.43 (g/cm³)

Luminescence:

Fluorescent. Deep Magenta-Red under SW UV and LW UV

Radioactivity:

Not Radioactive

Optical Properties

Color:

Brown red, Light pink, Pink

Transparency:

Transparent to Translucent

Luster:

Vitreous

Refractive Index:

1.640 - 1.710  Biaxial ( - )

Birefringence:

0.013 - 0.015

Dispersion:

Weak

Pleochroism:

X = Z = orange; Y = rose

Occurances

Geological Setting:

In manganese ores formed by metamorphism of manganese-bearing sediments with attendant metasomatism; typically associated with skarns.

Common Associations:

Rhodonite, Tephroite, Calcite, Glaucochroite, Johannsenite, Wollastonite, Diopside, Grossular.

Common Impurities:

Mg, Zn, Fe

Type Locality:

Tetela de Ocampo, Hidalgo, Mexico

Year Discovered:

1822

View mineral photos:

Bustamite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Bustamite is similar in properties and appearance to Friedelite and Rhodonite. It is found at several localities around the world but faceted gems are very rare and usually small. Cat's eye material is available but also rare. Bustamite is usually seen as beautiful reddish to pinkish cabochons. Its color is from the presence of manganese. Its cleavage makes faceted gems difficult to cut.

Sources of Bustamite are the "type material", from Tetela de Ocampo, Hidalgo, Mexico, is a mixture; well-studied material from other localities includes: in the USA, at Franklin, Sussex County, New Jersey. At Långban and in the Harstigen mine, near Persberg, Värmland, Sweden. At the Treburland mine, Altarnun, Cornwall, and in the Railroad quarry, Meldon, near Okehampton, Devon, England. At Camas Malag, Isle of Skye, Scotland. From Baita (Rézbánya), Romania. At Campiglia, Tuscany, and Schio, Vicenza, Italy. From the N'Chwaning mine, near Kuruman, Cape Province, South Africa. In Australia, at Broken Hill, New South Wales. From the Obori mine, Yamagata Prefecture; the Noda-Tamagawa mine, Iwate Prefecture; the Kanoiri mine, Tochigi Prefecture; the Mikumo mine, Shiga Prefecture; and the Hijikuzu mine, Iwate Prefecture, Japan.
 

  
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