2016 Jewelry Trends: Opals
Despite the world of fine jewelry being dominated by diamonds and colored gemstones such as sapphires, opals continue to become more popular among all age groups and styles. Opals vary greatly in color due to their ability to diffract light. It is said that no two Opals are alike.
The word Opal stems from the Greek work opallios, which means a “change of color”.
Opals rate 5.5 to 6 on the Mohs scale, which is only slightly harder than glass. The gem is usually mined from wet sources at lower temperatures and contains 5 to 9 percent water.
There are 3 types of Opals:
Common Opals
They do not exhibit many colors and look milky white.
They are found in many parts of the world.
Fire Opals
They exhibit warm colors ranging from yellow, orange to red.
Fire Opals mined in Mexico have a very distinct orange tone. 
Precious Opals
They are known to exhibit many colors, giving them a rainbow effect when viewed from different angles. Precious Opals are found predominantly in Australia. In fact, 95% of the world’s precious Opals are mined in Australia.
Black Opals, which are in this category, are some of the most precious and valued Opals as they have very interesting displays of color. 
Opal Infographic