Unheated sapphire vs heated—what would YOU do?? Part 1: This is a natural, unheated bubblegum pink sapphire is beautiful and completely untreated, which already makes it rare. But with heat treatment, there’s a chance it could become a deeper, richer pink and increase in value. Heating can improve color and remove visible inclusions, but ultimately it comes down to what the customer wants….so as a customer would you rather this stone be heated or unheated? | Assay Jewelry