When opals began gaining popularity in the 19th and 20th centuries, diamond merchants got nervous about losing business.
If you really want to test your jeweller, ask: "do you know what percentage of nickel is used in the alloy" as any percentage over 17% may irritate the skin to those with allergies to Nickel.
Opal Cutting and Polishing Procedure If you see yourself becoming an expert cutter, continue reading this extensive article which will introduce you to the methods and machinery necessary to pursue your goal.