Uses
Crystals and gems are most commonly used in jewelry pieces such as earrings, necklaces, rings and bracelets. They are also used as decorative features in clothing and home decor.
Characteristics
Specific characteristics of crystals and gems vary considerably. A crystal or gem may be large, small, durable, brittle, shiny or dull. Some appear transparent while others are colored.
Source
Crystals and gems are extracted from caves and mines around the world. However, scientists are now able to produce high-quality synthetic gems and crystals in laboratories.
Gem Types
There are about 16 specific types of gems that are determined to be the most highly valued. Among them are diamond, jade, garnet, topaz, quartz and opal.
Crystals
Crystals fall into several categories including molecular solids, metals, alloys, insulators, minerals and semiconductors. These categories are differentiated based on their tendency to rust.