Description
- Gems, Minerals
- Amethyst
- Rhodochrosite
- Tourmaline
- Petrified Wood
On June 3, 1974, in Lincoln, ND. the US Post Office Dept issued this Se-Tenant of four stamps, depicting Gems and Minerals of the United States Mineral Heritage. This was the first US stamps series designed by rotating the block 45 degrees to create a diamond effect. Included here are the Amethyst, Rhodochrosite, Tourmaline and Petrified Wood.