Antique Glass Waistcoat Ball Buttons - 7/16"

Glass Ball Waistcoat Buttons - 7/16" - Late 1800's - These little beauties have long been a favorite of mine. Some believe these types of buttons came from "Bohemia", Germany or the Czech Republic area of Europe - Some of the Waistcoats are Italian, French and from G.B. - I have several types of the buttons and seen them described as containing Sterling Foil, Foil, Flakes, etc. - In the marble collecting world, the marbles with these flakes are said to contain Mica. You see Mica in Hand Made 1800's Onionskins, End of Day's, Swirls and just Mica's. I have pictured one of my Green Mica's next to the Green Glass Buttons - In no way am I trying to say that I definitely know that that the material in these is Mica, but I suspect it is. Would love some feedback on this if anyone has knowledge - These types are also called Paperweights by some people, but I have them as Waistcoats - They have a solid base glass with a "Window" containing the Mica, Etc. - Long Brass Shanks and Plates