Dashiqiao magnesite deposit, Haicheng, Liaoning

The DTA curves of seven representative samples from the Kharidhunga Magnesite Deposit arc asymmetric and show a sharp rise after attaining the maxima between 670 and 700 oC, which indicates the siliceous nature of the magnesite. The overlapped endothermic peaks al 770 oC and 860 oC characterize the presence of calcite and dolomite respectively as the other impurities. The results of DTA and TG are also compared with the available data of chemical analysis.

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Genetic Environment of the Pailou Magnesite Deposit in Dashiqiao Belt, China, and Its Comparison with the Daeheung Deposit in North Korea

Economic and Environmental Geology ◽

10.9719/eeg.2021.54.6.767 ◽

2021 ◽

Vol 54 (6) ◽

pp. 767-785

Author(s):

Heonkyung Im ◽

Dongbok Shin ◽

Bong-chul Yoo

Keyword(s):

North Korea ◽

Genetic Environment ◽

Magnesite Deposit

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Deposition and transport of gold by thiosulphates, Veitsch, Austria

Mineralogical Magazine ◽

10.1180/minmag.1995.059.395.09 ◽

1995 ◽

Vol 59 (395) ◽

pp. 253-258 ◽

Cited By ~ 8

Author(s):

H. Kucha ◽

W. Prohaska ◽

E. F. Stumpfl

Keyword(s):

Grain Size ◽

Natural Environment ◽

Direct Evidence ◽

Average Composition ◽

Magnesite Deposit ◽

Primary Gold

AbstractTwo types of gold can be distinguished in tetrahedrite from the Veitsch magnesite deposit, Austria. Primary gold present in unfractured massive tetrahedrite, has a grain size up to 18 μm and contains, on average, Cu 8.73, Ag 7.01, Au 78.63 and Hg 2.35 (wt.%). Secondary gold is present in fractures and is directly intergrown with digenite, covellite, Cu-thiosulphate, cuprite and chrysocolla but not with malachite or azurite. The secondary gold is up to 200 µm in size with an average composition of Cu 3.06, Ag 6.82, Au 86.41 and Hg 3.51 (wt.%). It is usually closely intergrown with thiosulphates containing up to 0.21 wt.% Au. This, together with the presence of ‘dirty’ gold with cloudy thiosulphate inclusions, directly indicates the transport and deposition of Au by a thiosulphate ligand. We believe this is the first reported direct evidence of gold transport and deposition by thiosulphate complexes in a natural environment.

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