A particularly preferred grinding medium is a material commercially available under {HEAD ~ the name} YTZ Ceramic Beads, commercially available from {TAIL ~ S. E. Firestone Associates} 
A particularly preferred grinding medium is a material commercially available under { HEAD ~ the name } YTZ Ceramic Beads , commercially available from { TAIL ~ S. E. Firestone Associates }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL