Obsidian: Rocks we know we knowDec 21, 2017
$5.50 inc GST
Quartz formed by hydrothermal deposition during metamorphic processes in the Kin Kin beds. Examination under magnification will show the specimen to be a massive sample of tiny quartz crystals displaying all the typical features associated with quartz.
The small crystals are the result of fast cooling of the silica bearing liquid that intruded between the sedimentary layers of the Triassic Kin Kin beds. This is an excellent specimen to use in the classroom to compare with an amethyst cluster and discuss the differences in crystal formation due to fast and slow cooling. Follow up with a fast and slow cooling experiment in class.
This specimen comes from around Gympie in Qld where the deposits are historically well known to be gold bearing.
Cleavage: prismatic, almost at right angles
Specific gravity: 2.6 – 2.7
Images are examples of specimens only. Size and shape may vary.
Specimens are usually no smaller than 75mm in one dimension.
36 in stock