Also called “Amazon stone,” amazonite is the only microcline you’re likely to encounter as a gemstone. Microclines are potassium feldspars with a triclinic crystal structure. Amazonite color can range from pale green to dark green and blue-green.

With a hardness of 6 to 6.5, amazonites are softer than other common jewelry stones, like quartz and beryls. This means amazonites are still susceptible to scratching from everyday hazards, like household dust (which has a hardness of 7). With perfect cleavage, amazonites may also break if accidentally struck.

However, these gems will still make excellent jewelry stones for earrings, pendants, and brooches, which usually don’t receive rough wear. With protective settings, they can also make beautiful ring stones. Amazonites lack transparency, so they’re seldom faceted. Nevertheless, aficionados of opaque gems might appreciate the appearance and novelty of such a piece.

Brazil and Peru produce fine amazonites, but this gemstone also occurs in many localities across the world. In the United States, the area around Pike’s Peak, Colorado and Amelia Courthouse, Virginia produce beautiful, gem-quality amazonites.