We don’t normally endorse it, but in the last 12 months we have had quite an increase in enquiries for opals to be used in engagement rings.
The reason why we don’t normally support this is due to the softer nature of opal on whole. Given that opal has a mohs hardness rating of about 6.0, and diamonds have a rating of 10.0, we would normally suggest diamonds, given that engagement rings generally cop a lot of abuse from day to day wear.
However, if set correctly, opal can make a very attractive and unusual alternative.
We would always recommend a bezel/rub-over style setting for engagement rings, purely because claw/prong settings leave the opal more vulnerable and open for damage.
Also, using Boulder Opal would be recommended because of their higher durability (due to the natural inclusion of ironstone) compared to Black, Crystal or White opals. The freeform shape of Boulder Opal also leads to more interesting and unique designs.
If you are considering having an opal in your engagement ring, please think over the options I have presented. Also, have a look at the more recent engagement rings we have had made.