Rammelsbergite

NiAs2
c 2001-2005 Mineral Data Publishing, version 1

Crystal Data: Orthorhombic. Point Group: 2/m 2/m 2/m. Rare as prismatic crystals,elongated along [010], to 5 mm; commonly massive, granular, radial, fibrous. Twinning: On{101}.
Physical Properties:
Cleavage: {101}, distinct. Hardness = 5.5–6 VHN = 630–758 (100 gload). D(meas.) = 7.1(1) D(calc.) = 7.091
Optical Properties: Opaque. Color: Tin-white with a faint pinkish hue; in polished section,pure white. Streak: Grayish black. Luster: Metallic. Pleochroism: Weak, in yellow to pinkish
hue and bluish white. Anisotropism: Strong, especially in blues.
R1 –R2 : (400) 56.1–59.8, (420) 56.6–60.2, (440) 56.8–61.0, (460) 56.6–61.1, (480) 56.1–60.9, (500)56.2–60.8, (520) 56.5–60.8, (540) 56.8–60.9, (560) 57.0–60.9, (580) 57.0–60.9, (600) 56.9–60.6, (620)
56.8–60.1, (640) 56.6–59.6, (660) 56.4–58.9, (680) 56.6–58.5, (700) 56.7–58.0
Cell Data:
Z=2Space Group: P nnm (synthetic).

a = 4.7582(7)b = 5.7949(8)c = 3.5440(4)X-ray Powder Pattern: Synthetic (nearly identical to ferroselite).
2.552 (100), 2.476 (90), 2.843 (65), 1.870 (55), 1.696 (30), 1.771 (25), 1.790 (20)
Chemistry:NiCo
FeAsSbS

(1)
27.84
1.80
trace
67.32
0.83
2.03

(2)
28.6
0.5
0.1
71.0

(3)
28.15

71.85

0.4

Total 99.82
100.6
100.00(1) University mine, Cobalt, Canada. (2) Coniston mines, England; by electron microprobe.
(3) NiAs2 .
Polymorphism & Series:
Mineral Group:

Trimorphous with pararammelsbergite and krutovite.

Löllingite group.

Occurrence:minerals.

In hydrothermal veins formed at medium temperatures with other Ni–Co

Association:uraninite.

Skutterudite, safflorite, löllingite, nickeline, bismuth, silver, algodonite, domeykite,

Distribution: In Germany, at Schneeberg, Saxony [TL]; at Eisleben and Mansfeld,
Saxony-Anhalt; from Bieber, near Hanau, Hesse. In the Lölling-Hüttenberg district, Carinthia,
Austria. From the Polkovice copper mine, near Legnica, Zechstein copper district, Lower Silesia,
Poland. In France, at Sainte-Marie-aux-Mines, Haut-Rhin. From the Coniston mines, Cumbria,England. In the Leadhills-Wanlockhead district, Dumfries, Scotland. At the Sedmochislenitsimine, Vratsa district, western part of the Stara Planina (Balkan Mountains), Bulgaria. FromLainijaur, Västerbotten, Sweden. Large crystals at Bou Azzer, Morocco. In the USA, from theMohawk mine, Keweenaw Co., Michigan. In Canada, at the Eldorado mine, Great Bear Lake,
Northwest Territories; in various mines around Cobalt, Ontario, and other scattered localities. Inthe Ulsan mine, Kyongsang Province, South Korea. Known from a number of other occurrences
world-wide.
Name:To honor Karl Friedrich Rammelsberg (1813–1899), mineral chemist of Berlin, Germany.

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References: (1) Palache, C., H. Berman, and C. Frondel (1944) Dana’s system of mineralogy,(7th edition), v. I, 309–310. (2) Kjekshus, A., T. Rakke, and A.F. Andresen (1974) Compoundswith the marcasite type crystal structure. IX. Structural data for FeAs2 , FeSe2 , NiAs2 , NiSb2 ,and CuSe2 . Acta Chem. Scand., 28, 996–1000. (3) (1960) NBS Circ. 539, 10, 42. (4) Criddle,A.J. and C.J. Stanley, Eds. (1993) Quantitative data file for ore minerals, 3rd ed. Chapman &Hall, London, 473. (5) Ramdohr, P. (1969) The ore minerals and their intergrowths, (3rd edition),839–845.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted inany form or by any means, electronic, mechanical, photocopying, recording, or otherwise without the prior written
permission of Mineral Data Publishing.