This is the finest dioptase thumbnail for my taste, that I have handled. Roland and Kathy Sherman considered it to be among the best dioptase thumbnails period, when they obtained it. It is indeed a SUPERB dioptase with two balanced, prefect crystals perched on calcite. Each species has the best color and luster. Ex Zweibel personal collection, to the Jim and Dawn Minette collection in 1992 when the Zweibels sold their secret stash and retired from mineral dealing. The Minettes traded this to Roland and Kathy Sherman in 2001, where it remained since. It was in many prizewinning exhibits by both the Minettes and Shermans. A note on Roland's index card label adds: "Bought out from under me at the '92 Denver show by Minette!" - and he never forgot it!. From the Roland and Kathy Sherman thumbnail collection: they are competitive thumbnail exhibitors from Southern California, specializing in copper species. Joe Budd Photos