The “gem” of an ammonite dates back 71 million years, and comes with a curious coating of ammolite, giving it a dazzling rainbow iridescence. “A 'Gem' Ammonite in Matrix from the Bearpaw ...

In fact, iridiscent opalized ammonites are so striking that they have their very own mineral name: ammolite. Ammolite is biogenic gem material primarily found in Alberta, Canada. However ...