To drill a hole in Opal is not as simple as it sounds. We find many people buy Opal or Gemstones and try to drill a hole in it and don’t succeed. This can be very frustrating if the following procedure is not followed.
Here is a home made version made out in the opal fields Winton Queensland for drilling holes in boulder opals.
Its a dremel drill set up on a hand press shaft so it can be levered up or down. On the base he has set up adjustable drill shank to hold the bottom drill. This is a great idea as if anyone has tried to drill hole it is hard to get the holes to match up.
As if you try and drill all the way though the opal will chip at the end so this system is easy to make at home and to drill holes both ends of the opal and thy will match perfectly.
Diamond tip drills are suitable for drilling small quantities of Opals. These drill bits have been tipped with diamonds of different grades and shapes can be round, arrow pointed, long shape or hollow point. 120 grit is suitable for drilling holes.
These drill bits can be attached to any standard home drill or dremel drill but if the drill speed is set on high speed the diamonds will burn off in a matter of seconds. This happens frequently as there is incredible heat when a diamond drill bit touches the stone and it needs constant water on the stone when you drill. The drill must be on slow speed.
Standard home drill attachments that hold a drill are suitable but you will need a block to hold the Opal stable for drilling.
Standard diamond tip wheels can be purchased that are 3-4 inches wide and these are curved so semi shaped beads are formed. Most are 100 to 140 grit.
To start shape the opal, mainly boulder opal or ironstone opal with colour bars to a rectangular shape are best. This long rectangular shape fits against the diamond tip curved wheel by another attachment that can be spinning or manually turned. The result will be uniform beads with two blocks on each end that can be sliced off with a saw blade.
Many cutters do get disappointed when making beads as rough is usually good to start but, most of the colour disappears when making beads so make sure you use Rough Opal that has colour veins running through them as they normally produce a good finished bead.
This bead cutting machine will make the boulder opal beads perfectly round. First the cuter has to cut the opal into a rectangular shape to make the bead. If you have ever tried to cut an opal into a round shape you will realize how difficult this is.
I’m sure that you will agree that after you try and make some beads yourself you will appreciate why good quality Opal Beads are so expensive.
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