How To Make A High Quality Cabochon

Hi, my name is Judy Kiriazis and I'm founder and owner of Heart of Stone Studio, a website where we sell the highest quality cabochons from more than 50 different countries and hundreds of mines all over the world. Some of our cabochons are cut right at the source, but many of our stones entered this country as rough chunks of rock which were then transformed by professional cutters called lapidarists into the beautifully jewelry-ready pieces that you see on our site. Heart of Stone Studio carries the work of dozens of different gem cutters and we asked one of our favorites, our friend and Arizona lapidary artist, Keith Horst, to take us behind the scenes and show us how he makes a high quality gem cabochon from a humble piece of rough. Here's Keith in his cutting workshop. Hi, I'm Keith Horst. I am a local lapidary artist and a businessman. I sell my cabochons at gem shows and to Heart of Stone Studios. Today I'm going to show you how I make one of my cabochons. Today I'm going to show you folks how I cut a cabochon out of a certain type of material. Today I'm going to use some petrified or fossilized palmwood. The material palmwood as found or mined is actually a palm tree and you can see the rough material here has a bark of like a tree type look to it and the inside of it has been totally replaced with quartz or silicated. It's petrified wood if you please. The little dot patterns you see are actually the cell patterns in the wood. I'm going to take a slice off of a piece just like this with a large saw. That'll make a slab and I'll take that slab and I'll be able to design a cabochon from the slab. Here is a slab I took off another similar piece of the palmwood and now I am going to design a cabochon that I'm going to trim out of this slab. Here's a slab of the petrified palmwood we took off a larger piece. This is a nice bi-colored darker piece. It's exceptionally nice color on this piece. One of the most interesting parts about making a cabochon is coming up with the area on this slab where I think an interesting cabochon could be cut. This is a pretty interesting slab all the way around so I can't go too far wrong. If this had some flaws or inclusions or things I did not want to incorporate into my stones I'd have to plot them out or mark them out but this slab is nice and solid without any holes or fractures in it so about anywhere I make my stone is going to be acceptable. This is kind of a bi-color area and I like to capture the lighter color with a darker color so I'm using this very edge of the stone here. I have marked out a stone here a shape that I like. It's kind of a surfboard shape if you please. I like to cut kind of geometric type shapes. I'm doing this totally freehand. I'm not using a template of any sort however you could. Templates are these things. This is an architectural template. If I were cutting ovals obviously I have a selection of ovals and I would just place this template over the area of the slab I would like to cut the stone out of and then mark it usually with just a lead pencil or I will go over it with aluminum pencil which makes an indelible mark which will not come off when I'm grinding the stone and I'll be able to see the mark I've made with the aluminum pencil. I just made this mark here with a sharpie pen and I think it'll work good enough for me to trim it out with a trim saw. So the next step is we're going to go over to the high speed trim saw and trim this out of this slab. Hi here I go to trim this piece of palmwood this cabochon out of this slice of palmwood. I'm using my high speed five inch diamond trim saw today that uses a water-based coolant. It goes fairly fast it's a fairly safe operation even though it may look a little dangerous and it works pretty darn easy. I'm going to turn the machine on now it's going to make some noise so here we go to saw this piece. We're going to easily just take it off like that. Now we have a piece I can start grinding on. All right so right now we're going to start doing the initial grinding of the shape of this piece I just trimmed out with the other process. I'm going to be using my diamond grinding wheels on my big eight inch diameter grinding machine here. These are extra wide two inch diamond wheels there's two different grits of diamonds here the coarser grit is a very coarse aggressive grit it's about an 80 grit and the higher finer grits is about a 320 grit. I'm going to be starting out with the coarser grit to put the initial shape on this this stone. This all works off of a water type of flow to keep the heat and the friction down so this machine makes quite a bit of noise. I'm going to turn it on and adjust the water flow you'll see the water start coming out of it that's a good amount of water maybe too much. Now I'm going to start grinding the stone I'm going to hold it a little more than halfway down the diameter of the stone of the wheel this is going to make quite a bit of noise. These diamond wheels are very aggressive this is agate or a coarse on cutting and it can easily shape the quartz up really easy. By holding it parallel the cabochon parallel to the wheel and holding it in the proper position on the wheel I'm able to put a small beveled edge from the bottom of the stone to the top of the stone and that slight degree the angle will make it easier for a jeweler to set the stone so it's very important I hold this stone in the proper position which is a little more than halfway down the diameter of this wheel. I'm going to put a rough shape on it right now and I can tune that up with a finer wheel and I don't want to really grind too much more with this coarse wheel because it's very abrasive it's very coarse it's actually throwing a lot of chips off but you can kind of see the shape I'm getting right there on it already so now I'm going to go to the finer wheel right beside it here it's going to make a little different noise as you can hear I'm just going over the edges of the stone to take out the scratches that the coarser wheel has put on this edge of the stone and maybe true up the shape a bit more. I'm holding it absolutely parallel to the wheel about in the same position I'm not angling it by any means like that and I'm not grinding it up here or down here as soon as I think I have a lot of the scratches out on the side we're going to stop and do another process. Okay in this process we're going to be dopping a stone up in other words we're going to be attaching a wooden stick or a stone with this very hot wax which is melting with a light bulb underneath this platform here this is special wax called dop wax it melts at about 160 degrees and it has shellac in it which makes it very sticky so what we're going to do is we've preheated the stone up on this platform here we're going to take it off of that platform it's very hot now it's face side up I'm going to turn it over backwards I'm going to quickly take a dollop of wax on the dop stick and I'm going to make a mound of wax down in the center of the stone you can see it kind of draws it right down on the stone being the stone is hot I'm going to wait just a second or two for that wax to start getting a little tacky at that point I'm going to put the dop stick down in the middle of that puddle of wax I'm not pressing real hard on the stick I just placed it in that puddle and I'm waiting for the wax now to set up a little harder it'll take a it'll take a 15 seconds or so for this wax to cool down enough to where I can handle it and I can start pushing it down over the rest of the stone. All right in this process after we've dopped the stone up with this stick is we're going to be grinding the top of the stone to create our dome I cut in a low dome profile so to achieve that I'm going to be cutting at a 45 degree angle on this 320 grit diamond grinding wheel I'm going to be creating a a line all the way around the perimeter of the stone which takes off about half of the total thickness of this stone at a 45 degree angle like this this line has to be pretty straight all the way around it's like the foundation of your house that everything else is based on it goes pretty quickly with this particular wheel and at that point I'm going to be moving the dop stick down to a 90 degree angle putting it down a little lower on the wheel and starting on that line I just created and moving the stone up to the center of the wheel and that'll start doming the top of the stone I'll do that all the way around on all sides when I finished with that I'm going to have this fairly scratched surface from this diamond wheel but it's going to be domed nevertheless and it'll have some flat spots or facets on it that I will want to take out and I'll start taking those out by revolving the stone on the same wheel not changing wheels going like this which will smooth everything out nice and smooth okay this next process after we've ground the stone with the diamond grinding wheels we're going to start sanding the top of it lapidary is just a procedure of finer and finer scratches until you can't see them anymore so this is this particular belt or silicon carbide belt is going to remove the scratches that the diamond wheel has put on the top of this stone this is an eight inch by three inch rubber expandable drum and I put silicon carbide belts another sanding lapidary procedure on top of this belt here on the top of the drum and it sands the stone very effectively being that it's rubberized I can press into it pretty hard and it helps maintain the dome on this stone and it'll I have to sand the entire top of the stone so with that in mind I'm going to turn the machine on it's going to make a little noise I got the water going I'm just going to briefly show you how I sand the top of the stone I'm using quite a bit of pressure on it to get the scratches out and it's pretty quick if you do it correctly I have to stop and inspect frequently and dry it off to make sure I'm getting the scratches out I can't proceed to the next step until all the scratches are out of this stone if I proceed too soon to the next step where the scratch is still in the stone I will not be able to take the scratches out with a finer grit so I'd have to come back down to this step so I might as well get the scratches out now and the scratches will show up as a bright white line on this and I really don't see any bright white lines so I've okay so we've moved over to a different machine in my shop now this is a diamond pacific genie machine that uses a six inch diameter wheels and the wheels I'm going to be using to do the final sanding and pre-polishing on these are these nova wheels they're called a nova diamond wheel and this is diamond that's impregnated into this plastic and there's three different grits there's 600 to 1200 and a 3000 grit going up the scale here by the time I'm through with this 3000 grit the stone should be taking on a fairly good polish and we'll take it from there to another final polish pad this uses its own independent water system with a geyser type situation machine makes a little bit of a noise but it's still pretty quiet compared to the others I put these geysers under the wheel which sprays the water up underneath and I'm going to start sanding the top of this stone now I could have continued on with the diamond with my big silicon carbide belts that we were showing you before and got the finer and finer belts that works very good but I'm really fond of these diamond sanding wheels they're very popular there's a lot of machines made with these wheels these days and these wheels are very very good they're very forgiving they seem to do a very good job of taking out the scratches and they're very quick if you've done all your preliminary work right these will work very fast okay at this point I'm also just going to go over the sides of the stone a little bit to make sure they're going to be polished now normally I'd stop and check to make sure I was getting my scratches out I looked pretty closely before I started there wasn't too many scratches in it so I'm hoping we're not carrying any scratches any further we're going to go to the 1200 grit now that was a 600 grit this machine I can sit down at you'll notice the other machines I was using I was standing up I like the position your body is in when you're standing up with the bigger eight inch wheels with this six inch machine I find it's nice to sit down at so these machines are pretty quiet and they're clean once again I'm going to go over the edges real quickly oh boy all right I'm going to move right on up to the 3000 wheel without closely inspecting this I really should be looking a little closer at it I have a nice bright light here which is an inspection light I'm looking for any missed scratches or flat spots in the stone I have looked at it closely before this and I knew there wasn't any so we're looking pretty good so this final step here is a 3000 grit sanding wheel you see I'm keeping the stone moving fairly fast if I were to hold it in one place too long it would actually start sanding a flat spot which I don't want so I've got to keep it moving to make sure I'm not putting any flat spots on the stone once again I'm going to go over the sides a little bit I could have done these sides completely independent of the top if I wanted to finish the sides up before I dome the stone but I'm working them at the same time I'm doming them all right I've done everything correctly here this stone should be taking on a fairly good semi-polished and I don't know if the camera can pick that up or not but it's looking pretty good all right we're now going to put a final polish on this stone with a leather pad that I've put on the end of my bigger machine this leather pad I charge up with a special polishing compound which is an optical polish which is a really refined cerium oxide and it comes in liquid form I keep it in refrigerator from drying out and I'm going to apply a little bit of this liquid polish to this leather pad after I've turned it on I then will be taking my stone on the dopstick and just starting to polish the top of the stone by revolving it around on this leather pad that'll give me a really fine high polish a lot of lapidaries and a lot of people would think the polish I'm getting already off of that last wheel is going to be sufficient but if you've seen my stones I am a stickler for polish they have to be absolutely maximum polished and this will achieve that really quickly so we're going to turn the machine on I'm going to add a little bit of water with a spray bottle and then take the polish now as this dries out from the friction I'm going to have to add a little more water I don't want to add so much water to where the leather is really soppy wet I just want it wet enough to where it's slightly moist if I add too much water to it the stone will actually hydroplane over the leather and not polish I want it to grip the leather a little bit with a semi dried out leather pad I'm going to go over the edges of the stone at the same time too the polish coming off of this is just about perfect you can see it's almost dry in fact it is dry I can't even wipe it off that's actually a pretty good spot to be in all right so we've finished the stone I've taken I've removed it off the dop that process was just simple enough to put the dop with the stone attached to it in the freezer compartment of a small refrigerator here in my shop and after it's got cold after it's cooled down quite a bit the dop stick easily just breaks easily right off the back of the stone creating a nice clean back on it it's nicely polished nicely domed I washed it down with a toothbrush and some warm water and inspected it for any scratches and it's pretty scratch free it's a nice domed low dome profile like I like I'm probably going to go back over and finish up the sides a little better later on but for the top of the stone right now is absolutely perfect ready to go a lot of times lapidaries would leave it just like that but I'm kind of picky and I like to finish my stones up completely before I put them out for sale so this would take a little bit more work but it sure looks nice it came out really really nice and it came off of this nice slab of palm wood right there it came off right there you can see where it came off of I think it turned out really nice so as you can see a lot of precision cutting shaping grinding and polishing go into the creation of one single gem cabochon heart of stone studio carries the work of Keith Horst and other top lapidary artists who are both nationally and internationally known so when you visit our site heartofstonestudio.com know that you will be getting the best selection of high quality stones to enhance your jewelry designs