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Topics - RoughCreations

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Show off your Gems / "Diamond Nine" cut in citrine
« on: December 05, 2020, 03:48:35 PM »
Showing off my recently completed 27.2ct Tasmanian Gladstone citrine.
"Diamond Nine" Fusion-style cut taken from Andrew Brown's Faceting Design book (Volume 1).


Gemstone Faceting / Ebonite diamond lap review
« on: August 19, 2020, 07:19:09 PM »
This review follows on from a post by Giel:

Part 1 : The Unboxing

I received two disks from Bert in the Netherlands today, postage took a month to Tasmania under the current pandemic conditions. I purchased a 20/28 (800 grit) and a 63/80 (200 grit) disk. The following are my first impressions of the disks. Note that I have no interest, financial or otherwise, with the manufacturer of these disks.

The disks were packaged very well, there's definitely no way that they could get damaged unless a steamroller ran over the package.

Upon picking them up and handling them, my first impression was that these disks are very well made. They are manufactured by a craftsman. My next thought was that there's certainly nothing rubbery here - The cutting surface is very hard, there is no noticeable "give" when pushing hard with a fingernail, there is no way I would have picked the disk surface to be made of a rubber compound.

Apparently they are made out of "ebonite", a rubber with 40 to 60% sulphur, which after vulcanisation becomes rock-hard.

Because the diamond is embedded in rubber, the particles sink/spring back in the rubber when cutting, that is reportedly why they leave a very fine finish for the grit size. There is about 100 carats of diamond powder in a coarse lap. (less in the finer grits)
These laps are apparently suitable for cutting all gem materials.

The "sintered diamond" ebonite layer is 3 mm thick, attached to a solid 15mm thick backing plate made of some sort of tough, reinforced phenol resin material. The 3mm layer of diamond impregnated cutting material is comparable thickness-wise with a typical sintered bronze lap. The longevity of the impregnated ebonite layer is unknown at this stage - only time will tell.

The disk width is 150mm, and the central hole sits snug on my Facetron. There is no way you would get any flex in these disks. If these disks cut even half as well as they feel in the hand, it will be a win.

Now, I must add that I have never been lucky enough to have used/owned a traditional sintered bronze disk before, I have wanted to, but they are near impossible to source in Australia, and prohibitively expensive from overseas. So my comparisons will be with diamond-impregnated epoxy topper discs, such as the Lightning Laps and also with the ubiquitous Chinese-made diamond plated steel topper disks.

I see these disks potentially filling the gap somewhere between thin, short-lived topper disks and long-lasting sintered bronze disks. Coming in at a fraction of the price of the bronze disks (assuming you can even get them), if these disks cut nicely and last even moderately well in comparison, then they will be very competitive.

I believe that these ebonite disks can also be re-surfaced by the user with a sheet of glass and some wet and dry paper, thereby extending their lifetime.

I cut mostly quartz, and given its brittle nature, I guess if these disks perform well with quartz, they should work with most materials.

Stay Tuned for Part 2: The Cutting Begins...

Show off your Gems / Xoval 1.19 cut in smoky quartz
« on: April 26, 2020, 03:49:00 PM »
Just finished an Xoval 1.19 design in smoky quartz from Andrew Brown's first book.
Very happy with the results. It was pretty straightforward to cut. Anyone see the X?
Weight 39ct
L 24mm x W 20mm x H 15.5mm
Tasmanian Gladstone smoky quartz

Show off your Gems / Stargazing Cut in smoky citrine
« on: April 02, 2020, 10:58:44 AM »

Probably better starting a new thread:
Stargazing facet design smoky citrine ready for transfer. No problems so far, looking sparkly, preview of performance can already be seen in middle picture.

Gemstone Faceting / Facetron mast ball bearing
« on: March 02, 2020, 11:53:57 AM »
Hi, a basic question for Facetron owners out there, is the machine supposed to have a ball bearing sitting in the top cup-shaped indentation of the mast (see image of my machine below)? The micrometer adjuster in the mast sleeve pivots here. I was reading a post on another forum where someone mentioned the ball bearing, so it alerted me to a potential problem. If so, what size bearing goes in? I might have lost it when I removed my mast in the past...


Gemstone Faceting / Info on Batt Lap
« on: December 20, 2019, 02:15:12 PM »
I recently scored a second-hand Batt Lap as shown in the pictures, I thought Batt Laps were all a solid tin alloy but this one has a 2.3mm coating of a dark grey composite material on top of the aluminium backing plate. When would this have been produced, and do you use this lap any differently to a solid tin alloy Batt Lap?

General Discussion / Unpleasant Gemstones
« on: December 04, 2019, 11:58:50 AM »
Recently during my web travels I came upon a gemstone website from Jaipur, India. It had the sentence:
We source unpleasant gemstones specifically from the mines and do additionally esteem option in cutting and cleaning, studding them into perfect jewellery
Puzzled initially, it came to me that it was an unfortunate English translation for rough gemstones!
Then I thought to myself, does my website, Rough Creations, sometimes translate to Unpleasant Creations?

Gemstone Faceting / Can anyone id this facet head?
« on: July 09, 2019, 06:45:25 PM »
I was given this facet head some time ago, no other parts - it seems to work OK, was just wondering if anyone knew what machine/model it was from, and approximately how old it might be?


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