This museum could be so much more. It has a number of interesting showcases that show different gems in different states of refinement. It also has an interesting way of showing which gems are found in different regions. Finally, it has a few interesting displays (call them dioramas on steroids) showing the traditional use of the gems.
But. It would...
My favorite place to buy gems and jewelry is Kuang Sint Yadanar in the Myanmar Gem Trade Center. They also have a second location just across the street from Gem Museum
No.66 Kabaraye Pagoda Road , Yangon Myanmar
By the way the family owners of this shop have not been involved government.