Sand Blasted it is indeed! Of course, its not "sand" really, though, its aluminum oxide.Looks like they just sand blasted it, I like the texture.
What do you have going researchkitty
That is "hand made" Serendipity (Northstar Amber Purple over Northstar Star White), with white dots, then sandblasted. Since Amber Purple *is* a striking color (aka has metals in it!), the piece will fume itself inside and out while you make it. You'll notice a lot of my oil dome / slide have "fumey" looking joints, thats all the metal in the color vaporizing out and hitting the warm joint and sticking! The reason we know its hand made Serendipity versus pre-made crucible double dipped tube is because of the lines down it. Dipped tube wont have the lines, vac stac tube will.Definitely some neat work. Is it fumed or just colored glass?