Gemstone
Definition
A mineral or organic material that has been cut and polished for use in jewelry or decoration. Valued for beauty, rarity, and durability.
Example
Diamond, ruby, sapphire, and emerald are precious gemstones.
What Makes a Stone a Gem?
A gemstone is a mineral, rock, or organic material that has been chosen for its beauty, durability, and rarity, and then cut and polished for use in human adornment. While there are over 4,000 minerals on Earth, only a small fraction are considered gemstones. To be a gem, a stone must be beautiful (color, brilliance, pattern), durable enough to withstand wear (hardness and toughness), and rare enough to be valuable.
Precious vs. Semi-Precious
Historically, only four stones were considered "Precious": Diamond, Ruby, Sapphire, and Emerald. All other gemstones were labeled "Semi-Precious." This distinction is scientifically meaningless and often misleading in terms of value. For example, a high-quality "semi-precious" Tsavorite Garnet or Paraiba Tourmaline can be far more expensive than a low-quality "precious" Emerald. Modern gemology focuses on quality and rarity rather than these antiquated labels.