Turquoise prices per ounce vary based on availability, carat, quality, grade and rarity. One carat of turquoise is equal to .007 ounces and is priced by grade and carat.
Turquoise is used for a variety of purposes, the most popular of which is jewelry work. Turquoise can be mounted in metals such as gold or silver, but the stones must be of a very high quality and are considered very rare. As of 2014, turquoise of this quality, known as "gem grade," can range from $40 or more per carat, or per .007 ounces.
Lower grade turquoise, such as very high grade, high to average grade, average grade and stabilized grade, are far less costly because the stones aren't often considered rare. Though the turquoise may have the same luster and shine as a gem grade stone, it may not be the same color quality or matrix balance. According to Turquoise Sky, stones in these grades can vary anywhere from $3 per carat to $20 per carat and can be used for purposes such as costume jewelry or lower grade home accents.
Turquoise is considered a precious stone, though most of the turquoise on the market comes from operating mines, making them fairly inexpensive.