There are a few different types of gemstones, such as Natural Gemstones. Natural gemstones are found in nature, created by natural forces. These gemstones are quite often more expensive than the other types of gemstones. Laboratory-Created Gemstones. Labratory-created gemstones are manufactured in a lab. Also called laboratory-grown or synthetic stones, they have the same chemical, visual and physical properties as natural gemstones. They are more common than stones produced by nature and are usually less expensive than stones that are mined. Imitation Gemstones. These artificial gemstones are usually made from glass, plastic, or less expensive stones, even though they may look like the real thing, don't be fooled into paying the real price.
There are a number of gemstone treatments or enhancements that are used to improve a stone’s appearance, durability or color. Among these treatments are dyeing, bleaching, heating and irradiation. Be sure to ask your jeweler whether the stone you want to buy has been treated. You need to know whether the treatment is permanent or not, whether the treatment means the stone requires special care, and how the treatment may or may not effect the value of the stone.