Pearl and opal have been valued as gems throughout history and across many cultures.
Pearls are unique among gemstones. It's the only gem material found within a living creature, they require no cutting or polishing before use.
The most familiar are white and cream, but the palette of colours extends to every hue. Natural pearls form around a microscopic irritant in the bodies of certain mollusks.
Cultured pearls are the result of the deliberate insertion of a bead or piece of tissue that the mollusk coats with nacre.
Opal on the other hand is the product of seasonal rains that drenched dry ground in regions such as Australia’s semi-desert “outback.” The showers soaked deep into ancient underground rock, carrying dissolved silica (a compound of silicon and oxygen) downward.
During dry periods, much of the water evaporated, leaving solid deposits of silica in the cracks and between the layers of underground sedimentary rock. The silica deposits formed opal.
Opal is known for its unique display of flashing rainbow colors called play-of-color. There are two broad classes of opal: precious and common. Precious opal displays play-of-color, common opal does not.
These beautiful objects have chemical compositions a bit different than most gems and require special attention before, during, and after cleaning.
Pearls and opals are beautiful gems, but if they seem overly fussy to you, don’t despair. Check out some steps you can take to keep you and your jewelry content for many years at Gemsociety.org.