Better 1000-6000 degrees i think and about glowing effect - you can use lava glow.

hmm...
I also know that quartz is used in analogue watches, I think the way it vibrates or something is useful for determining how long one second is. I have thought of it as a suggestion, but I dont actually know what it would do...
maybe it could be a pulse delayer, so we don't need water in walls and/or diamond.

Hmm... if there is such a push from allot of users for electrolysis, quartz could maybe be used as the new delaying thing, like a very slow conductor and it would only accept a new current after several seconds...
(all of these ideas occurred to me as i wrote this post)

no, sand is not made of silicon. The main component is silicon dioxide, also commonly known as Silica.
technically sand has quartz in it, but only very small crystals.