Yogo Sapphire - Montana's "Goldilocks" Gem Yellow, pink, green, and purple corundum specimens are all sapphire (red corundum is called ruby), but the most valued varieties are deep blue. Gem dealers seek cornflower blue, nearly a reflection of Montana’s Big Sky.
Montana History From Lewis and Clark to Fort Piegan: The 25-Year-Long War between Mountain Men and the Piikáni (Piegan) Blackfeet
