Can You Identify this Rock?

Elise Kellett submitted a photo of a rock she's had in her possession for many years, collected from the desert near Dhahran. Out of curiosity, she is hoping someone can identify the type of rock. She says, "my husband found this rather weird looking, glassy stone which weighs well over a kilo, Can anyone identify it? The central hole goes almost right through it. It would have required tremendous heat to cause this. (If you see gold flecks ignore them. I painted it gold some years ago. It is so heavy I used it as a doorstop.)"

If you have a guess as to what type of rock this is, please reply in the comments below.