A thin layer of opal is sandwiched between a layer of clear quartz and a layer of either obsidian or ironstone. An opal triplet is an opal doublet with a quartz layer on top. Triplets must be cleaned very carefully. Opera-length generally refers to a string of pearls that hangs to the breastbone. ORA Ora was a costume jewelry company founded by Oreste Agnini in Chicago, Illinois in 1927.
Early pieces are unsigned.
Ora went out of business in the 1960's. The Ora earring above is studded with clear rhinestones.