A Guide to Terms for Gem-Buyers

Some important terms for gem buyers:

Synthetic--Lab-grown stones that closely duplicate a natural gem’s physical and chemical properties. They easily can be confused with the genuine item, though they’re often less expensive. Some well-known synthetic gems include Chatham emeralds and Kashan rubies.

Simulated--Another type of man-made stone. Although its color may be similar to that of a natural gem, it’s very different physically and chemically. Colored glass is often used to imitate such precious stones as rubies or sapphires. Cubic zirconia is a well-known diamond simulation.

Enhanced or treated--When the natural gem is altered in some way to improve its look. Color can be enhanced through heat, radiation, oils and chemicals. Liquid glass is sometimes used on diamonds to cover up noticeable cracks, a relatively new process known as fracture filling.