Second Natural Occurrence of KFeS 2 (Hanswilkeite): An Inclusion in Diamond from the Udachnaya Kimberlite Pipe (Siberian Craton, Yakutia)
Potassium sulfide KFeS 2 (hanswilkeite) has been identified in polymineralic inclusions in a diamond from the Udachnaya kimberlite pipe (Siberian craton, Yakutia). This is the second occurrence of hanswilkeite in nature and the first one in mantle-derived samples. Sulfide KFeS 2 is monoclinic, the s...
| Published in: | Minerals |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
MDPI AG
2023
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| Subjects: | |
| Online Access: | https://doi.org/10.3390/min13070874 https://doaj.org/article/47fc0d1fd30f481fab7fe89b124d501b |
| Summary: | Potassium sulfide KFeS 2 (hanswilkeite) has been identified in polymineralic inclusions in a diamond from the Udachnaya kimberlite pipe (Siberian craton, Yakutia). This is the second occurrence of hanswilkeite in nature and the first one in mantle-derived samples. Sulfide KFeS 2 is monoclinic, the space group—C 2/c. Its crystal structure consists of chains with K in the interstices. The tetrahedra are centered by iron ions and linked by edges, thus forming chains of [FeS 2 ] frameworks. The strongest lines of the electron diffraction powder pattern are 7.05 Å—(200); 5.34 Å (0 <semantics> 2 ¯ </semantics> 0); and 3.05 Å (2 <semantics> 2 ¯ </semantics> 0), and the angles between directions are <2 <semantics> 2 ¯ </semantics> 0/0 <semantics> 2 ¯ </semantics> 0>—60° and <2 <semantics> 2 ¯ </semantics> 0/200>—30°. KFeS 2 has been found as a discrete phase within polymineralic inclusions consisting of apatite, ilmenite, chondrodite, phlogopite, dolomite, and a fluid phase. The data obtained from the composition of the hanswilkeite (KFeS 2 ) inclusion and other rare minerals (chondrodite, Mg-apatite, Cr-ilmenite) in primary inclusions in a diamond from the Udachnaya kimberlite testify to the important role of metasomatic processes in diamond formation. |
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