You have to try this, I was told.
The packet of glass was labelled "Buffy."
I have a dog named Buffy, you see. Although she is not this colour. She is mostly inky black with a sprinkling of sand in her fur and tan points.
However, the name was amusing. ;-)
When working it - it appears to get a layer of transparent topaz on the top.
It's variability serves it well in rapid cooling situations, i.e. in brass presses and molds, see the three faces in the top left.
Oh, and because you asked - this is the real Buffy.