Purple Quartz: Wholesale Buyers, Industrial Uses & Expert Resources

Question
I recently found a 40 lb chunk of purple quartz in a piece of land I have and am suspecting I may find lots more.

Q.1. Do you know of an industry directory/conference/association for wholesale quartz and/or gold buyers?

Q.2. Do you know which industrial uses purple quartz has?  I think its used in water filters but not sure.

Thanks

Answer
Sorry this is totally out of my expertise... Rock cutter's have a lot of knowledge on these kind of things... Also, geologists if you can find one... Another possibility is calling the Gemological Institute of America in Carlsbad, California...
I would keep the location of this find a secret until you really determine the value and usually that would take 2 to 3 opinions..
Regards Rolfe