Let me rephrase this, so that I can give an answer.
Originally Posted by CR1000
Is it possible for a planet to be covered so that the surface is nothing but silicon dioxide dust or grains, and that it could go through a brief period of being heated high enough to melt the sand, but not enough to boil the sand, and that it will eventually cool off again so that there is a layer of glass (some meters, or perhaps even kilometers thick)?
Answer: it is very implausible, but not strictly speaking totally impossible.
Forming opinions as we speak