Demantoids are the green variety of andradite garnets. Their colors range from yellowish to brownish green to intense green and have a greater dispersion or “fire” than diamonds. They can also contain distinctive yellow “horsetail” inclusions of radiating fibers. If placed attractively within the stones, these can increase their value. Demantoids rarely occur in sizes larger than three carats. Prices for demantoids can also rival those of emeralds. They can go from a few hundred per carat in smaller sizes to over $10,000 per carat in larger sizes. Demantoid garnet crystal, Iran. Photo by Smallru. Licensed under CC By-SA 4.0.