Riddle Me This (1)

[Moonlight]

I'll probably be posting my riddles in separate threads, since there are no ways to make Spoilers on Proboards. First Riddle:

I am cold, hard. I can be solid or hollow, clear or colored. I can be melded into useful or simply decorative things.

I never age, nor do I change. When broken, I am dangerous.

What am I?

[128Up!]

When I read this small puzzle, the pieces they slide,
The material's identity, isn't easy to hide.
Although you try to be a clever lass,
It's obvious that you're masquerading as glass.

[Moonlight]

Hehe, clever way to answer, Niichan.

[Admiral Titus]

Well, you had me for a second, but the "When broken I'm dangerous" Gave it away.

As well as Phil's epic answer.

I look forward to more in the future.