The dominant equilateral triangle face (each side measuring 15 mm) shows the classic growth patterns typical of Burmese rubies. It fluoresces red under UV.

Illustrated at Figure 1 in “Ruby Deposits: A Review and Geological Classification” by Gaston Giuliani, Lee A Groat, Anthony E Fallick, Isabella Pignatelli & Vincent Pardieu published by MPDI on 20 June 2020: see https://www.mdpi.com/2075-163X/10/7/597. It is there stated to come from Bawpadan, Mogok & the photo is credited to Louis-Dominique Bayle © le Règne Minéral. The piece features in Figure 1 of the article, which contains examples of rubies from six different localities worldwide (out of a total of 70 sources listed in Figure 2 of the article): the specimen is the example offered for rubies from Myanmar.

Photos by László Kupi