Crystals are really pretty and some say they have healing powers. 
Oh really? Ive been interested in crystals lately, I love how they look especially as decorations. Whats your favorite color crystal? 
My favorite are black crystals like obsidian. The best way to use them is to have a variety of colors like a chakra.  
Thats cool, I light the brighter colored ones myself. Where do crystals come from exactly? 
Depending on the type of stone they can be formed in different places. Obsidian is a form of igneous rocks formed from volcanic glass. 
Oh in volcanoes! thats wild. I hear that a lot of natural crystals form deep underground. Have you ever watched the documentaries where they go to the crystal caves?
I haven't watch ed all of it, you have to pay for all but the first episode! 
Oh no, well that stinks, Do you know what is the biggest crystal ever discovered? 
I do not, but have you heard about the crystal oscillator? They use the frequency it omits to track time.