Gypsum var. Selenite on Gibbsite from Laochang Mine, Yunnan, China

Dimension: 3.2cm x 3.2cm x 1.8cm
Weight: 50 carat / 10g
Locality: Laochang ore field (Laochang Mine), Gejiu Sn-polymetallic ore field, Gejiu Co., Honghe, Yunnan, China
 
A rather rare prismatic Gypsum var. Selenite on Gibbsite specimen discovered with a few others in late December 2020, from Laochang Mine, Yunnan, China.  A heavily crystalized Gypsum var. Selenite which has a monoclinic tabular crystal structure, perfectly perched onto a striking matrix of blue Gibbsite.  This rare Gypsum and Gibbsite combination is well-balanced and very attractive in person.  Comes with a high quality acrylic display box.
 
Gibbsite was first discovered in 1820 by Chester Dewey (1784-1867) of Williams College, Massachusetts. It was first thought to be Wavellite, but a year later it was determined to be a separate mineral species and was subsequently named Hydrargillite. It was then renamed Gibbsite in 1822 by John Torrey (1796-1873) in honor of George Gibbs (1776-1833) of New Haven, a noted mineralogist whose important collection was acquired by Yale University.