Turquoise is a secondary mineral; that is, a mineral that undergoes a chemical change and takes on a new form. Turquoise deposits slowly build up as acidic water seeps through another mineral such as copper. Thus, a lot of turquoise beads are not originally from turquoise mines at all but from mineral mines that stumbled upon a pocket of turquoise. Most turquoise is found in dry places since weathering leaves cavities in which turquoise can build up.

Southwestern United States is one of the best places to find high quality turquoise beads. Sadly, many turquoise collectors worry about how long that will last as more and more turquoise mines become exhausted. Nearly all the turquoise currently being mined is low grade, but high quality turquoise stones and jewelry are still circulating in the market place. Some of the most beautiful American turquoise beads are from Nevada, valued for their deep blue color and black spider web matrix. Also notable are the turquoise beads from the Sleeping Beauty mine in Arizona, which produces sky blue turquoise without any matrix at all.

Iran has produced some of the finest turquoise in the world for the last 2,000 years. If there were such things as perfect turquoise beads, they would come from Iran. Turquoise from Iran is a solid, vivid blue that has not been discovered in any other region. Only turquoise beads from southwestern United States come close to the quality of Iran turquoise beads. Interestingly, turquoise in the United States is often found in copper while turquoise in Iran is often found in trachyte.

Sinai has been known for turquoise since ancient Egyptian times and it is still called the Country of Turquoise in some areas. The turquoise of Sinai is often found in either sandstone or copper. Miners on the Sinai peninsula have a rather high mortality rate due to flash flooding and extreme heat being added to the normal risks of mining. However, only a few small mines are still operating as turquoise becomes more scarce.

China produces more turquoise beads than any other country. Grades and colors vary widely depending on the mine, but all Chinese turquoise is generally soft. Therefore, turquoise from China has to be stabilized to be shaped into beads. These turquoise beads are affordable and easy to find compared to the places previously mentioned. While many places produce blue to blue-green turquoise, China is one of the few countries that also produces a bright green variety of turquoise.