Editorial Feature

Bursaite - Occurrence, Properties, and Distribution

May 20 2014

Bursaite was named after the original locality of the mineral in Bursa Province, Turkey.

Properties of Bursaite

The following are the key properties of bursaite:

Cell Data
- Space group: Bbmm
- a = 13.399(20)
- b = 20.505(10)
- c = 4.117(5)
- Z = [2]

Crystal Data
- Orthorhombic
- Point group: 2/m2/m2/m
- Prismatic crystals, up to 4mm, and platy elongated grains
- partly in radial or polycrystalline aggregates
- Twinning: Common, with twin plane || [001], possibly {110}
- Lamellar
- X-ray powder pattern: 2.048 (100), 2.998 (78), 3.670 (67), 3.484 (67), 2.696 (67), 2.794 (44), 3.127 (33)

Chemical Composition

Elements	Content 1	Content 2	Content 3
Pb	45.0	45.03	46.57
Bi	38.5	37.43	37.58
S	14.7	15.53	15.85
Ag	1.0	1.41	-
Sb	-	0.61	-
Total	99.2	100.01	100.00

Optical Properties
- Anisotropism: Strong, in gray-bluish and yellowish colors
- Pleochroism: Weak, white with blue tint, brown to light gray
- R₁–R₂: n.d.

Estimated Properties

Electron density	Bulk density (electron density) = 5.29 g/cm³ note: Specific gravity of bursaite = 6.40 g/cm³
Photoelectric	PE_Bursaite = 1,582.31 barns/electron U=PE_Bursaite x ρ electron density = 8,366.87 barns/cm³
Fermion index	Fermion index = 0.1 Boson index = 0.9
Radioactivity	Bursaite is not radioactive

How to Identify Bursaite

Bursaite can be identified in the field by its gray color. Its opaque form has good cleavage. This mineral has a metallic luster.

The density of bursaite is 6.2 g/cm³ with a hardness of 2.5 to 3 - between finger nail and calcite.

Global Distribution

Bursaite is distributed in the following places:

Turkey - From Uludag, Bursa Province
Sweden - At Boliden, Vasterbotten
Italy - From Vulcano, in the Lipari Islands
Czech Republic - At Hurky
Russia - In the Shumilovsk Sn.W deposit, western Transbaikal, and from the Strezhana pyrite-polymetallic deposit
Romania - From Baita
USA - At Organ, Dona Ana Co. New Mexico; large crystals in the Abril mine, Middle Pass district, Cochise Co. Arizona; from near Austin, Reese River district, Lander Co. Nevada; in the Cofer deposit, Louisa Co. Virginia
Argentina - From the Huemules deposit, Chubut Province

Occurrence of Bursaite and Useful Mineral Association

Bursaite occurs in a contact metamorphic scheelite deposit; in sulfide veinlets around a greisen Sn–W deposit in granite; and in a volcanogenic massive sulfide deposit.

It is often associated with minerals such as sphalerite, tremolite, pyrite, calcite, garnet, scheelite, chalcopyrite, kobellite, wolframite, cassiterite, tintinaite, bismuthinite, galena, cosalite, heyrovskyite, galenobismutite, cannizzarite, tetradymite, joseite-B, bismuth, and quartz.