crystals in an HDR

Steven Gibbs called me today and said his cat likes to attack his ball of magnet wire. He says he should get his cat Felicia a ball of yarn. I like to use crystals in an HDR unit, but they are hard to buy and are very expensive. Good double terminated quartz crystals are rare. Steven Gibbs gets them from a large Arkansas mine. Most have fractures and cracks so he throws them away.