Christite

TlHgAsS3
c 2001-2005 Mineral Data Publishing, version 1

Crystal Data: Monoclinic. Point Group: 2/m. As subhedral grains, to 1 mm in length.
Some grains are somewhat bladed or flattened, probably on {010}.
Physical Properties:
Cleavage: Perfect on {010}, excellent on {110} and {001}, good on{101}. Fracture: Uneven. Hardness = 1–2 VHN = 28–35 (10 g load). D(meas.) = 6.15
D(calc.) = 6.37
Optical Properties: Opaque to semitransparent. Color: Bright orange to deep red orcrimson, darker than realgar; yellowish orange with red tinge, tarnishes brown; in reflected light,grayish white with pale blue tinge, with red or yellow to yellowish brown internal reflections.
Streak: Bright orange, yellow. Luster: Adamantine.
Optical Class: Biaxial. Pleochroism: Weak to strong, grayish green, dark violet, bluish violet.
Bireflectance: Pale gray with blue to yellow tinge.
R1 –R2 : (470) 29.3–30.1, (530) 26.6–26.7, (590) 25.2–26.1, (460) 23.8–24.7
Cell Data:

Space Group: P 21 /n. a = 6.113

b = 16.188

c = 6.111

β = 96.71◦

Z=4

X-ray Powder Pattern: Carlin mine, Nevada, USA.
2.98 (100), 3.62 (80), 4.03 (60), 3.49 (60), 2.692 (60), 3.36 (50), 2.216 (50)
Chemistry:TlHgFeZnCu

(1)
35.2
35.1

(2)
35.29
35.46
0.10
0.02
0.02

(3)
35.48
34.82

CdAgAsSe
S

(1)

13.1
16.6

(2)
0.04
0.08
12.23
0.03
16.57

Total

100.0

99.83

(3)

13.00
16.70
100.00(1) Carlin mine, Nevada, USA; by electron microprobe, average of four analyses; correspondingto Tl1.00 Hg1.01 As1.01 S3.00 . (2) Lanmuchang deposit, China; by electron microprobe, average of 13analyses; corresponding to Tl1.00 Hg1.02 As0.95 S3.00 . (3) TlHgAsS3 .
Occurrence: In hydrothermal barite veins and in mineralized carbonaceous silty dolostone(Carlin mine, Nevada, USA); in thallium-rich pods in a stratabound mercury deposit(Lanmuchang deposit, China).
Association: Realgar, orpiment, lorandite, barite, getchellite (Carlin mine, Nevada, USA);lorandite, barite, marcasite, pyrite (Lanmuchang deposit, China).
Distribution: In the USA, in Nevada, at the Carlin mine, 50 km northwest of Elko, Lynndistrict, Eureka Co. [TL], and in the Getchell mine, Potosi district, Humboldt Co. At theLanmuchang Hg–Tl deposit, Guizhou Province, China. From Alšar (Allchar), near Rošden,Macedonia.
Name: To honor Dr. Charles Louis Christ (1916–1980), American physical chemist,
mineralogist, and crystallographer with the U.S. Geological Survey.
Type Material: Geology Department, Stanford University, Palo Alto, California; National
Museum of Natural History, Washington, D.C., USA, 144272, 144273.
References: (1) Radtke, A.S., F.W. Dickson, J.F. Slack, and K.L. Brown (1977) Christite,a new thallium mineral from the Carlin gold deposit, Nevada. Amer. Mineral., 62, 421–425.
(2) Brown, K.L. and F.W. Dickson (1976) The crystal structure of synthetic christite, HgTlAsS3 .
Zeits. Krist., 144, 367–376. (3) Li Xi-lin, An Xian-Guo, and Nan Jun-Ta (1989) The second
discovery of christite in nature. Kexue Tongbao, 34(11), 942–945 (in English).
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.