Sometimes it also shows play of color in addition to its bright orange body color. Low quality opal was recently discovered in Ethiopia. Opal is cut in Australia, Hong Kong, Mexico, Germany, and other places. Calibrated sizes are widely available in light opal, which is very popular with jewelry manufacturers around the world due to the beauty even of inexpensive pieces. Black opal is cut in free sizes due to its rarity and high value.
Boulder opal is often available in the natural shape of the rough.
Fire opal can be found in both faceted and cabochon cuts, including many interesting fancy shapes. A green translucent opal that resembles chrysoprase or jade, which is called prase opal, is found in Tanzania. A beautiful blue-green opal is found in Peru in the Andes Mountains. These types of opal do not display play of color. The hardness of opal ranges from 5.5 to 6.5 on the Mohs scale.