Not every bride prefers a traditional diamond. More couples today are choosing engagement rings that feel personal and ...

Agates are formed inside of rocks made by volcanoes, called igneous rocks. It may take thousands of years for water, thick with the mineral silica, to seep into the rock’s holes and create an agate.

And moss agate, which gets its greenish tint from traces of the mineral hornblende, resembles lush forests. (Mr. Adlakha noted that less than 1 percent of all agates display exceptional, ...