RUBY

 Rubies are found in metamorphic rocks, specifically in corundum-bearing rocks like marble and schist. Major sources include Myanmar (Burma), Sri Lanka, Thailand, and, more recently, Mozambique and Afghanistan. Rubies form in high-temperature, high-pressure environments. The red color comes from chromium traces within the corundum crystal structure. Due to its hardness, ruby is highly suitable for various types of jewelry, including rings, bracelets, and necklaces. Its durability ensures it maintains its luster and beauty over time. Ruby has a hardness of 9 on the Mohs scale, which makes it one of the hardest gemstones.