I have an unfortunate tendency to cut “doorstops”, which in the faceting world means cutting a mighty big gem, such as the 50 carat amethyst shown here.

When a piece of rough asks to be cut into a gemstone, I always feel that I would like get the maximum-sized stone from the rough, regardless of a few inclusions, as they always add a bit of interest or a few additional flashes to the finished result.

BUT…….. cutting big pieces of quartz and not having any kind of pre-forming grinding wheel, makes for difficulty. Often a fair bit of the rough must be removed on only certain sides of the stone once it has been centrally dopped in order to get it into a basic working shape. This is both time-consuming for me and hard-wearing on my 260 Cristalite laps. Coming from more of a lapidary, stone-carving, background, I am used to using 4” Velcro backed diamond encrusted pads (which come in grits from 50 to 3000) to do the work of removing excess stone on my large carving work. The ease with which the diapads wear down stone of all hardnesses, made me think that perhaps they could speed up the removal of rough from my gems too. I work with a Raytech faceting machine, and first tried the 200 grit 4” discs that I already had but they didn’t cover enough of the lap when it came to cutting girdles. Recently I went back to my supplier and found that there is also a 200 grit 6” (approx. 15 cm) diamond encrusted pad available, and this fits exactly onto the lap area of my faceting machine. Despite the apparent gap between the pads (see photo), and the high pitched humming noise that occurs when a chunk of dopped rough is first put on the surface, it is remarkably fast in removing excess rough. Once the basic shape and the beginning of the break facets are in place I can return to a 260 grit Crystalite lap and then cut down sufficiently to remove any scratches made by the 200 diapad and then go straight on to the 1200 Crystalite for fine cutting.

It is comparatively inexpensive and well worth a try for the occasional “doorstop”. JW