A few of you folks know I am a stone bead maker but few know about the thousands of hours of my life I have spent in front of an ultrasonic drill making bead holes. ultrasonic "drill" is a bit of a misnomer as the machine cuts the hole using a very high frequency small amplitude up and down motion using very hard fine (220) silicon carbide grit in a hammering action. The correct mix of grit , water and the proper hand motions , a bit up and down to wash out the spent grit and ground up stone and a small bit of rotation to maintain hole symmetry vary by type of stone drilled , how deep you are in the hole and how much the bit has worn.Practice makes the motions and choices second nature but recently I have decided to makes huge beads with 10mm holes , a far cry from the 4mm biggest holes of the past. the hole cores are big enough to drill out themselves with a 2.5 mm bit for smaller beads.I practiced with a slab of relatively soft limestone to practice various strategies and then drilled some jade,jasper and grossular garnet. My drilling efficiency improved dramatically after this practice. Eventually these big holes will be drilled in the same mindless intuitive manner that has served me so well over the years. If you look closely at the drill cores picture you will see some square glass cores as I am practicing making square holes again as well.Bead on!!!