The following are the major different types of emeralds, most are distinquished from their place of origin. Of note if the Cat's Eye emerald and the Star Emerald or Trapiche emerald, which are truly stunning.

Cat's Eye emeralds
Cat's eye emeralds exhibit a cat's eye effect. Cat's eye emeralds are very rare, and only exist for paler green emeralds. Chatoyancy is the industry term used to describe the optical effect of a wide slit that looks like the eye of a cat.

Colombian emeralds
Columbian emeralds is from Colombia and is known to be of exceptional quality.

Brazilian emeralds
Brazilian emeralds come from Brazil and are generally a lighter color than the Colombian emeralds. Note that the term Brazilian emerald may also refer to green tourmaline from Brazil.

Star emeralds
Star emerald is usually a term that refers to a trapiche emerald, but may also refer to the rare occurrence of an emerald displaying asterism. Asterism is an optical effect that appears as a 4, 6, or 12-rayed star which moves around when the emerald is rotated.

Trapiche emeralds
Trapiche emeralds are unusual emeralds containing black impurities in the form of a six-rayed star. Found only in the Muzo mining district of Colombia

Zambian emeralds
Zambian emeralds are quality emerald from Zambia.