Authors: Bindi, Luca; Cipriani, Curzio

Source: European Journal of Mineralogy, Volume 16, Number 5, 2004 , pp. 834-837(4)

Publisher: E. Schweizerbart'sche Verlagsbuchhandlung

Abstract:

Museumite, ideally Pb₅AuSbTe₂ S₁₂, is a newly identified mineral from the gold-telluride deposit of Sacarîmb, Metaliferi Mountains, western Romania. The mineral occurs as anhedral to subhedral grains up to 300m in cavities and vugs of large nagyágite crystals and it does not show any inclusion or intergrowth of other minerals. The associated minerals are nagyágite, hessite, sylvanite, petzite and coloradoite, whereas the gangue minerals are calcite and quartz. Museumite is dark silver-grey in colour and shows a grey-black streak. It has a perfect {001} cleavage, the fracture is hackly and the Vickers hardness (VHN₁₅) is 42 kg/mm². Museumite is greyish white in reflected light, with very low bireflectance and pleochroism. With crossed polars it shows distinct anisotropism, similar to nagyágite, but slightly stronger. Internal reflections are absent. Reflectance percentages for R_min and R_max are 38.4, 40.3 (471.1 nm), 38.1, 40.1 (548.3 nm), 37.5, 39.4 (586.6 nm), and 35.9, 38.0 (652.3 nm), respectively. Museumite is monoclinic, space group P2₁ or P2₁/m, with the following unit-cell parameters: a = 4.361(2) Å, b = 6.618(3) Å, c = 20.858(9) Å, = 92.71(5)°, V = 601.3(5) ų. The strongest five powder-diffraction lines [d in Å (I/I₀ ) (hkl)] are: 4.80 (52) (013); 3.56 (100) (111); 3.47 (58) (112); 2.99 (50) (023); 2.56 (41) (116). The average of 25 electron microprobe analyses gave Pb 52.0(4), Au 10.7(1), Sb 6.2(2), Te 11.7(2), S 19.4(2), total 100.0 wt. %, corresponding, on the basis of total atoms = 21, to Pb_5.00Au_1.08Sb_1.01Te_1.83S_12.08.

Keywords: MUSEUMITE; NEW MINERAL; SACARÎ MB; ROMANIA; NAGYÁ GITE-BUCKHORNITE

Document Type: Research article

DOI: http://dx.doi.org/10.1127/0935-1221/2004/0016-0835

Publication date: 2004-01-01

More about this publication?

• Editorial Board
• Information for Authors
• Subscribe to this Title
• Terms & Conditions
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Geology
• By this author: Bindi, Luca ;  Cipriani, Curzio

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers