https://en.wikipedia.org/wiki/Myanmar#Extractive_industries
> Myanmar produces precious stones such as rubies, sapphires, pearls, and jade. Rubies are the biggest earner; 90% of the world's rubies come from the country, whose red stones are prized for their purity and hue.
The article that is cited is from 2010, seems like overall gem production has decreased significantly since then.
https://www.statista.com/statistics/1061659/myanmar-producti...
I assume that's hyperbole because I couldn't find a list of top producing countries that included Myanmar, do you have a link?