Gemmes

Gemmes, or gemstones, are mineral or organic materials that are cut and polished for use in jewelry or decorative objects. The term derives from the French gemme and the Latin gemma, meaning a bud or jewel. Most gemstones form by natural geological processes and are selected for beauty, durability, and rarity. They fall into broad categories of minerals (for example diamond, ruby, emerald, sapphire, aquamarine, and quartz varieties) and organics (such as pearl, amber, jet, and coral).

Quality and identification depend on several factors. The color, clarity, cut, and weight—often summarized as the four Cs in the diamond trade—are used to evaluate value, though these criteria apply to many stones. Additional properties include hardness on the Mohs scale, refractive index, dispersion (fire), pleochroism, and cleavage. These characteristics influence appearance, wear resistance, and price, and help distinguish natural stones from synthetics or simulants.

Sourcing and treatment are integral to the gem trade. Gemstones are mined from primary deposits in rock or from alluvial gravels, and après-mining they may undergo treatments to enhance color or clarity, such as heating, irradiation, diffusion, or coatings. Ethical sourcing and disclosure of treatments are increasingly emphasized by industry bodies and markets.

Synthetic and natural varieties coexist in commerce. Laboratory-grown stones replicate natural crystals in composition and properties, while simulants imitate appearance without matching mineralogy. Disclosure is common practice in many regions to ensure informed purchasing.

Uses and significance vary by culture and purpose. Gemmes most often serve as jewelry focal points, but diamonds also have important industrial applications due to their hardness. They attract collectors, investors, and researchers, reflecting a long-standing human interest in color, form, and rarity.