Throwback Thursday

Remember these?

"Slocum stone" or "Slocum opal" is an early opal simulant - named for its inventor John S. Slocum - which was briefly popular before Gilson and other imitation opals came into the market. Chiefly seen in jewelry from the 1970's. Psychedelic and cool!

Slocum stone pictured below weighs 14.40 carats and measures 22 x 15.25mm.