Economic importance of crystals?

Question

for science/geography

Answer 1

What kind of crystals?

I think you can recognize the importance of sugar and salt in your everyday life.

Or how about modern electronics? With just a few exceptions,  they are built on a base of mono-crystalline silicon.

Or consider steel. The purpose of many of the alloys and the heat treatments, etc. is explicitly to affect the crustal structure:

http://en.wikipedia.org/wiki/Steel

In nature, the difference between clay and sand is the size of the crystals making up the material. Good soil needs a mixture - you can't grow anything in clay, and only a few things grow in sand.

Most abrasives are crystals - diamonds are the most famous, but, of course, there is also quartz in the form of sand.

And the list goes on.