FAQ
Where do opal gemstones come from?
Precious or sedimentary opal primarily originates from Australia, which produces over 90% of the world’s supply.
Other sources include Ethiopia, Mexico, and Brazil, but those regions produce mainly hydrophane or volcanic opal.
The difference between sedimentary and hydrophane opal is in their respective formation.
Sedimentary opal is vastly more stable due to it’s water content being trapped within the stone.
Hydrophane opal is volcanic and has a structure more like that of a sponge. Moisture is able to fill the voids and evaporate freely from structure.
What does “play of color” mean in opals?
“Play of color” refers to the vibrant flashes and shifting colors seen when an opal is viewed from different angles. This optical phenomenon is caused by the diffraction of light within the stone’s silica structure.
How is the body tone of an opal determined?
Body tone describes the base color of an opal, ranging from black, dark, to light or white and crystal. Crystal refers not the stones structure, as opal is amorphous, but to it’s appearance being more transparent or translucent.
The scale runs from N1 to N9, N1 to N5 being black. N6 through N9 gradually lighten from dark to light to white.
It significantly affects the opal’s overall appearance and value, with black opals generally being the most prized.
What does the brightness grade tell me about an opal?
Brightness measures the intensity of the play of color in an opal, graded from B1 to B5.
B1 shows the least intense color and B5 can be absolutely eye popping increases the value immensely.
How should I care for and maintain my opal gemstone?
All opals should always be handled carefully. Australian sedimentary opal is a bit more forgiving in many aspects. Their structure is hydrated silica, meaning that water is trapped within so nothing gets out or in. They can tolerate moderate high and low temperatures. As cold as my shop gets in the winter I haven’t seen any crack due to the cold. The only time I have cracked an opal was from overheating it when attaching them to a dopstick.
It’s pretty durable stuff much like the country it comes from and the people who mine it.
Cleaning is as easy as a quick polish with a soft cloth or a bit of warm soapy water.
Loose opal or jewelry should be stored separately in the soft bag or padded container so nothing can scratch or chip the stone.