At its simplest, a gemstone is a mineral (or occasionally an organic material) that has been chosen for its beauty, durability, and rarity, then cut and polished to be used in jewelry or adornment.
Think of it as nature's "survivor"—a piece of the earth that managed to withstand immense pressure and heat to come out looking spectacular.
The Three Pillars of a Gemstone To be classified as a true gemstone, a material usually needs to hit these three criteria:
Beauty: This includes color (the most important factor), clarity (transparency), and fire (how it reflects light).
Durability: It must be hard enough to resist scratching and tough enough not to shatter. This is measured on the Mohs Scale of Hardness (Diamonds are a 10; Sapphires are a 9).
Rarity: If it’s found everywhere, it’s just a rock. The harder it is to find, the more "precious" it becomes.