Custom Goldstone Pendants

About 12 months ago I cut a small oval monkstone cabochon for a friend of mine at work. It was a fairly small stone, from memory perhaps 34mm x18mm, and it was cut at her request as it was one of her favourite stones. Her intention was to have the stone set by a jeweller.

Goldstone (sometimes referred to as monkstone) is a man made material with official origins dating back to seventeenth century Italy. The 'stone' sparkles or glitters as a result of the tiny metallic copper crystals within. The most common form of Goldstone is a reddish brown colour but it can also be found as a deep navy blue.

Unfortunately, not long after I cut the stone for her, her house was robbed and her jewellery box was taken. The stone I had cut for her was inside the jewellery box at the time. I only discovered this recently when she asked if I was able to cut her another piece. This pendant is the result:

Free From Teardrop Goldstone Cabochon Pendant

Although this picture isn't brilliant, you can see the sparkle or glitter within the cabochon. The material is made by melting together silica, copper oxide, and other metal oxides. This mixture is melted down in a vat to chemically reduce the copper ions to elemental copper. The vat is then sealed and the material is allowed to remain liquid long enough for the crystals to form. Once opened, the material hardens into what is seen above. You can find more information on Goldstone here.

Subsequently, my friend has asked for another couple of pieces which I have now cut for her.

This is a blue goldstone heart finished with a sterling silver bail:

Blue Goldstone Free Form Heart Cabochon Pendant

And this is an 18mm round Amethyst cabochon which she is giving to her daughter in law for Christmas:

18mm round Amethyst Cabochon Pendant

The amethyst is set into a small silver plated bezel setting.

For more pendants and cabochons please check out my facebook page and Storenvy store. You can also follow my blog to keep updated with all my lapidary work!

Bye for now!

Preparing for a massive market

I was recently accepted as a stall holder for a large annual market held at the Pleasant Street Primary School in Ballarat (Australia).

Christmas Fest by the Lake 2012 is a massive market that is held each year by the Primary school and is used as one of their major fundraising efforts for the year. It is a market that attracts thousands of people every year with a vast array of attractions for families.

To prepare for this event, I have been cutting like mad whenever I get some free time! Unfortunately spare time has been harder to come by than hens teeth of late. With a trip to Echuca for a long weekend with family, then a trip to Sydney for my 5th wedding anniversary, in between a full time job (working plenty of weekends) and 2 kids under 4, finding time for cutting has been difficult to say the least!

I managed to get off work early yesterday though, and today being Saturday, I have been able to get a few bits cut:

Along with a whole bunch of other cabochons and pendants, the above pieces will be available from my stall at the market on Friday afternoon from 5pm - 9pm.

Whatever is left over will also be with me at a smaller festival the following day as I will also be holding a stall at the Gordon Tick-Tock Festival. This is an event to celebrate the re-awakening of the Post Office clock after 35 years in Gordon, Victoria (which is the small country town to which I call home).

It would be great to see you there!

Jaka Gems: Find us on Storenvy and Facebook!

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Cutting a rare Australian mineral - Gaspeite

Gaspeite - An extremely rare Australian mineral

I was recently talking to a friend of mine and we were discussing various different stones. She mentioned that she had seen a bright green stone pendant at a jewellers which she loved and asked if I could cut some for her. She couldn't remember the name of it, but said that it was apparently a very rare stone from Western Australia. I couldn't think of anything off the top of my head, but after we both did a bit of googling we figured out that the mineral she was talking about was Gaspeite.

Although the mineral was originally discovered in Canada, one, very small deposit of the nickel carbonate rock was discovered in the West Australian Desert. The Australian Gaspeite from that deposit is considered to be amongst the best and is the most sort after.

Gaspeite has a Mohs rating of approximately 4 1/2 to 5 making it relatively soft. I found it quite similar to cutting serpentine, and it was just as messy.

The Rough:

After a bit of searching, I managed to track down a small, cuttable piece of Australian Gaspeite from a dealer in Melbourne:

Australian Gaspeite Rough from Western Australia

Initially, I was a little bit disappointed with the piece once it arrived as it had a number of large cracks that ran quite deep. You can see one of the cracks in the photo above, which was the one of most concern to me.

The Custom Design:

After showing my friend the rough, we figured out what sort of shape she wanted, and that she was hoping to get a set to have a pendant and earrings made.

Here is the resulting cabochon set made up of 3 rectangular cabs:


Set of 3 Australian Gaspeite Cabochons

It turned out that my concerns about the cracks were warranted in some regard - you can see the remnants of one of the cracks in the small cab on the right in the picture. In saying this, it ended up giving the pieces a little bit of character with the small cracks and depressions surrounded by a nice polish. The stone itself polished well and was soft and easy to cut.

An Extra Cabochon:

After cutting the cabs for my friend, I had enough material left over to cut a free form cabochon:
 

Free Form Australian Gaspeite Cabochon

The crack in the middle of the stone seen above is the remnants of the large crack visible in the photo of the rough, but again I think it gives the piece a bit of character.

In the end, I didn't mind cutting Gaspeite; It finishes well with a nice shine (although plenty of other stones get a much higher polish) and it was relatively soft so was easy to cut. The above free from cabochon is currently available for purchase via my store:

Gaspeite Cabochon

And dont forget to check out my facebook page:

Jaka Gems on Facebook

Until next time!

How to cut a stone cabochon - Bloodstone Cabachon

A How-To Guide on Cutting Gemstone Cabochons

So how do you make a cabochon out of a rough chunk of rock?

Cutting a cabochon involves cutting and polishing a semi precious gem stone into a polished piece of rock with one flat side and one domed side. It is a fairly simple process once you know what you are doing, but it does take quite a bit of practice to perfect.

This is my quick guide on how to cut a stone cabochon which will hopefully give you some sort of idea on how the process works.

Equipment:

Essentially, the equipment that you will need is a lapidary trim saw (or a converted tile saw) and a cabochon machine. The other bits and pieces that are needed include a template and a scribe to mark out the shape of your cabochon on the stone. You may also want a waterproof apron because of the spray from the machines.

Safety Note: It is also worth noting at this point that precaution needs to be taken when cutting some stones and as a result, safety equipment such as eye protection and face masks may be needed. A couple of examples of this would be Nephrite Jade (which is closely related to asbestos) and Bumblebee Jasper (which has a high sulphur content).

Robilt Trim Saw

This is my trim saw, it is an old Robilt machine that belonged to my Grandfather. I recently had to rebuild the base. It is equipped with a 6 inch diamond blade and has a reservoir of water to keep the blade and stone cool whilst cutting. I also use an anti corrosion agent mixed in with the water to help lubricate the blade and to keep it all from rusting. 

CabKing Cabochon Machine

The cabochon machine I use is called a CabKing 6v3 (www.cabking.us). It is set up with 6 vertical wheels of varying grits and a polishing pad attached to the right hand side. These machines can be purchased via Aussie Sapphire (www.aussiesapphire.com.au) for around $2000.

The other machine that you may need is a slab saw (I have an old Robilt one that also belonged to my Grandfather) but slabs of rock are easy enough to come by without worrying about the expense of a large slab saw, which can become quite costly. Head to any gem show and you will find plenty, or search online.

If you don't like the sound of the $$$$ for the machines, a simple and cheap alternative is to join a local gem or lapidary club who have all the required equipment and plenty of experienced people to teach you the tricks of the trade.

Start up:

Heliotrope (Bloodstone) Rough

Captain Obvious: Start with a chunk of rock!


This is the piece we will work on today, it is a piece of Heliotrope (commonly known as Bloodstone) which originates from India. Heliotrope is a form of chalcedony which gets its nickname from the red inclusions of iron oxide or red jasper which look like blood splatters (see below).





Heliotrope (Bloodstone) Slab

The first step is to slab the chunk of rock into thin slices. It is generally accepted that either 1/4 inch (6.3mm) or 1/2 inch (12.7mm) is the standard thickness for a slab. My preference is for either the 1/4 inch or the 1/2 inch slabs, depending on the size of the cab (the thicker being better for large cabs and thinner better for smaller cabs).
 

The next step is to mark out your preferred cabochon shape and size using a scribe and template

Bloodstone slab marked for cutting

For this example I decided to go with a simple 35mm x 18mm oval standard cabochon. When being taught at a gem club, the simple oval shapes are generally the first that are taught with your first stone most likely being a 30mm x 40mm cabochon.

Basic Shape:

Heliotrope (Bloodstone) Rough 'Preform'

Using the trim saw, roughly cut out the general shape of the cabochon from the slab. It's best to remember that a saw blade is a bucket load cheaper than new wheels for your machine, so the more you take off the stone at this point, the less you need to take off with your diamond wheels.




Now it is time to move on to the cabochon machine. The most important part of the cabochon process is that you need plenty of water running over the diamond wheels. Without water, you will ruin your diamond wheels which can be a very costly mistake!

Metal Bonded Diamond Wheels on a Cabking 6V3

The first three wheels of the machine (pictured to the right) are used to shape the stone into a domed cut stone. The first two wheels are metal bonded diamond grinding wheels, the first is 80 grit and the second is 220 grit. The third wheel is a 280 grit resin bond diamond wheel.





Grind the remainder of the excess material from around where you have marked the shape, remembering to use plenty of water.

Bloodstone Shaped 'Preform'

At this point in the process, many people will attach the stone to what is known as a 'dop stick', which is basically a piece of dowel. You attach the stone to the dop with jewelers wax (some use 2 part epoxy glue, particularly with smaller stones) making sure that the stone is level and the dop is centered. I prefer not to dop, but that is simply a personal preference. I do however need to dop smaller cabs, ones that are too small to handle on their own. It is also common practice at this point to mark the center of the stone (on the top side) and to mark a line around the girdle just above the base of the stone. This helps the cutter maintain a standard height of the girdle around the edge and to help cut towards the middle of the dome. Again, all of this is personal preference.

Creating the Cabochon:

Cutting of Bloodstone Cabochon

Using the diamond grinding wheels, grind away the sharp edges of the stone, starting at a 45 degree angle.
You will end up with a 'flat' face right the way around the stone, and you will also end up with 2 edges instead of one.

Cutting of Bloodstone Cabochon

Follow the same process to remove the 2 new edges.
Keep working on the edges that are created by the grinding wheels by working the stone around the wheel.

Cutting of Bloodstone Cabochon

Eventually you will end up with a domed piece of stone................

Which looks something like this when dry:

Cutting of Bloodstone Cabochon

If you look closely, the white bits on the picture above are actually scratches made by the tiny diamonds in the wheels. You can only really see them when the stone is dry, but with experience you will be able to feel them when the stone is wet and wont need to dry it each time you need to check if they are still there. The next wheel (the 280 grit resin bonded wheel) cleans a lot of these bigger scratches off. In this following picture, you can see that I have run the top half of the stone over that 280 grit wheel:

Cutting of Bloodstone Cabochon

Cutting of Bloodstone Cabochon

The stone after the 280 grit wheel:

As you can see, all of those bigger white scratches have been removed by the 280 grit wheel. If you were to look closely, you would see that the stone is still covered with tiny white scratches, but they are a lot smaller than in the photo above. This is why the stone still looks quite dull.

Pre Polish: 

Resin Bonded Diamond Wheels on the Cabking 6V3

The next three wheels on the machine are for the pre polish. All three are resin bonded wheels with grits (left to right) of 600, 1200 and 3000. Essentially what each wheel does is put finer and finer scratches on the stone to give it a shine, these wheels also smooth off any ridges or edges left by the courser grit wheels. Again, you need plenty of water running over each of the wheels to lubricate.

Cutting of Bloodstone Cabochon

The stone after the 600 grit wheel:

Cutting of Bloodstone Cabochon

After the 1200 grit wheel:

Cutting of Bloodstone Cabochon

 And after the 3000 grit:

Final Polish:

2 Gram Syringe of 14,000 Grit Diamond Paste

For the final polish I use a canvas polishing pad coupled with 14,000 grit diamond paste which is purchased in 2 gram syringes. Many cabbers will follow the previous steps up to 100,000 grit, then polish with cerium oxide paste.

Canvas Polishing Pad attached to end of Cabking 6V3

The pad attaches to the side of the CabKing machine (as seen in the picture to the right). The final polish is the easiest part of the whole process, but if you have missed any scratches in the previous steps, they will stick out like the proverbials after the polish! You simply start the machine and run the whole stone over the polishing pad for a couple of minutes. Water is optional at this point, however if you decide not to use water you need to take care to ensure that the stone doesnt heat up too much as this may cause the stone to crack or break.

Don't forget to put a small beveled edge (on a 45 degree angle) on the back of the cabochon to avoid chipping:

The final product:

Finished Heliotrope (Bloodstone) Cabochon

All that is left to do is take a nice photo of the cab - I am still working on this bit - my wife is a far better photographer than I!

Finished Heliotrope (Bloodstone) Cabochon

Thanks for checking out my blog! I hope that you have got something out of this 'crash course' in cabochon cutting. The above stone is available for purchase through my store here along with plenty of others. Please also check out my faceboook page aswell - www.facebook.com/jakagems

Feel free to leave some feedback, let me know how I can improve this how to guide, or let me know if you have any questions!

Until next time!

Opal for a friend

I recently received a fairly cryptic message from a good friend of mine. Something to do with wanting a 4 carat opal cut for a ring she wanted to get made. She sent me a couple of pictures of a ring with an opal surrounded by what appeared to be rubies, or perhaps garnets.

Opal engagement ring which belonged to actress Sharon Tait

She told me after a few more messages that the ring in the picture belonged to actress Sharon Tate (Sharon Tate on Wikipedia), who was wearing the ring when she was murdered in the late 60's.

We figured out that without knowing the exact measurements of the stone, I wouldn't be able to get it exactly the same size, which was no issue. I also mentioned that the opal in the picture appeared to be of pretty high quality and that whatever rough opal I had would not be of the same standard. This was also of no concern.

As this person is one of my closest friends, I went pretty much straight to work. I picked out a nice looking piece of rough jelly opal from Coober Pedy (South Australia). Here are some photos of what the end result was (bearing in mind that all I had to work on was the picture above):

Opal cabochon for replica of Sharon Tate's engagement ring

Opal cabochon for replica of Sharon Tate's engagement ring

Opal cabochon for replica of Sharon Tate's engagement ring

This opal is what is known as Jelly Opal and it originates from Coober Pedy in South Australia. 97% of the worlds opal is mined in Australia with 80% of that coming from the mines of South Australia including Coober Pedy, Andamooka and Mintabie.

Unfortunately I am hopeless at taking photos of opal to get the colours to show. This piece does actually have a fair bit of flashy reds, blues and greens, but they don't really show up in these pictures. Clearly the stone is not the same sort of quality as Sharon Tate's ring, but I think I got the shape pretty much right. The one I cut ended up being roughly 6.4 carats and valued at around $25 AUD per carat.

I will be heading up to Sydney for a few days next week and will be handing over the stone to my friend while I am up there. She has already organized for a jeweler to make the replica of the ring for her. Hopefully it all works out and the ring turns out as nice as the original!

You can check out more of my opal cabochons in my store by visiting www.jakagems.storenvy.com or on facebook at www.facebook.com/jakagems

Thanks for viewing!

Until next time!

The beginning of the end perhaps?

I probably should start this blog with an explanation as to what Jaka Gems is and what it means to me.

I have been surrounded by rocks in various forms for as long as I can remember. My Grandfather started a business some 50 years ago selling rocks, minerals, crystals, fossils and all other related goods. He continued with the hobby until the day he died. I have collected rocks, mainly mineral specimens, for many many years and have quite a large collection at home, and ended up with most of the stock from the shop when my grandparents passed away.

But my real passion lies with Lapidary:


lap·i·dar·y  (lp-dr)

n. pl. lap·i·dar·ies

1. One who cuts, polishes, or engraves gems.

2. A dealer in precious or semiprecious stones.

adj.

1. Of or relating to precious stones or the art of working with them.

2.  a. Engraved in stone.

     b. Marked by conciseness, precision, or refinement of expression: lapidary prose.

     c. Sharply or finely delineated: a face with lapidary features.

I have been cutting stones and cabochons for more than 10 years, a skill that I have picked up from various people, not least of which is my Mum, whom I regard as one of the best opal cutters you will come across. I was a member of the Diamond Valley Gem Club for a number of years (located in Greensborough - a North Eastern suburb of Melbourne) until I moved house. Diamond Valley is where I learnt to do things properly, even trying my hand at some silversmithing. These days I am a member of the Ballarat and District Gem club, but rarely have the time to get there.

It is a pleasure to turn a rough piece of rock into a polished piece of art, and it is one of the most relaxing activities I have ever come across. It is something I have been able to lose myself in, and I quite often lose track of time in the process, something which my wife is none to pleased about.........

It was mid September this year (2012) that I decided that I would share this passion with others and start a small hobby business. My wife said to me that she had thought about it previously and that it should be called Jaka Gems (Jaka coming from our two first names JAmes and KAte), and thus my little venture was born! I started out by creating a facebook page (www.facebook.com/jakagems) and it has now grown into an online store via Storenvy (www.jakagems.storenvy.com). It has been suggested by a couple of people that I should start a blog that goes hand in hand with these sites, so here it is!

This is, and most probably always will be, a part time thing. Purely a hobby that I am hoping to share with others (and perhaps make a little bit of pocket money on the side!). Through this blog I will be sharing with you some of the pieces that I cut and some of the experiences that I have. I will also try and impart some of knowledge about stones that I have learnt over the years.

Here is a bit of a taste of what I do:

This is a small Rhodochrosite cabochon that I cut for my 3 year old daughters birthday on the weekend just gone. Rhodochosite is a mineral found worldwide (this particular piece originates from Broken Hill in New South Wales) and is quite soft in nature. High quality specimens can be blood red and very stunning. The bail on this piece is a sterling silver pinch bail, I simpy drilled a small hole through the cabochon to attach the bail.

 

Update 12/11/2012 - I cut a few more Rhodochrosite cabochons this afternoon and have attached similar bails, the bails on these are slightly bigger, as are the cabs. Rhodochrosite is one of my favorite materials to cut. It is soft which makes it easier, but still takes a really nice shine, which in my experience is uncommon for softer materials.

If what you read above interests you, feel free to follow my blog, or to checkout either of my facebook page or my Storenvy store. You can also contact me via my email address: jakagems@hotmail.com

Also feel free to comment!

Until next time,

James