Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
Quote:
Jon, I like the pink and green flashes. I want to try this material. Who did you get it from? I saw Tom Schneider and John Garsow carrying it.
Pretty Rock had a piece..I do not know if they have more. I like this stuff. It has a high RI, and the pictures do not do it justice because it has to be moving for the color flashes to really show up. I have always had trouble getting decent sized clean pieces, and many I have ended up with are very thin and not worth cutting.
It's easy to cut and polish and a lot of fun when it first comes off the dop...One os never SURE exactly what it will look like.
Joined: Sat Sep 29, 2007 8:14 pm Posts: 1383 Location: Royal Oak, Michigan US
Have been recutting a few stones lately. One of the pieces from yesterday was a very vibrant colored Spessartite. It was stated to be from Nigeria, but sure looks like Namibian to me. My duty was to salvage the maximum size, and weight and attempt to close the culet. Started like this....
And finished like this....
Very little touching up on the crown, but girdled the stone over my 8K BATT lap to give it a nice finish.
Original specs on the pavilion: four tiers in an all step cut design at 53* / 38* / 33* / 23*. I then changed to 47* / 41* / 37* / 20* to bring the culet together, but of course allows a little light to pass through.
This was originally a jamb-peg faceting job as the 96 index wasn't close to 180* from the 48 index. Same for the 24 / 72 line-up. Since I was going to have to chase each one down, I eliminated all the existing facets and placed/re-set my own so that they were in symmetry with one another, and allowed me to easily go back and find them to polish.
The look of the original finish was similar to my 8K on BATT ( and it could have been on copper or another type/metal). I finished it with 14K on BATT. Only a slight improvement but in keeping with the balance of the stone.
It would never pass the "new work" sniff test, but well enough for a recut project going back into its mounting.
Okay, since I don't have time to cut stones right now least I can post some pics of pre/post cutting from back in October.
The two stones in question are spessartites. The light one is a Loliondo spess from Tim's original sale of stones last year. I've included both a rough and somewhat cleaned photo so you can see the inclusiongs I'm talking about. I almost abandoned this one half-way through the pavilion because of a horrendously-large black inclusion with white stress spawl marks around it. On the dop it looked terrible but luckily I decided to press on. It turns out to be almost invisible at a distance due to the brilliance.
The darker stone was from jayinasia - another spessartite that is referred to as Lucozade (after the drink - available in Asia). These rough stones are very interesting and I refer to them as "brain garnets". This stone has a fair amount of inclusions but again they do not really show due to the dispersion and brilliance.
I was surprised how much lighter the Loliondo spess turned out, and very pleased with the colour and tone of the brain garnet. Both were standard SRB with a bit of BOG optimization - I used 40 and 38 for the pavilion, and 38-34.2-21 for the crown.
Small one is 1.07 ct and exactly 6.0 mm in diameter. Original 4.24 ct for 25% retention. Large one is 2.44 ct and 7.8 mm in diameter. Original rough was 6.53 ct for 37% retention.
_________________ Allan Aoyama http://www.omnifaceter.net <- Omnifaceter is back online!
Joined: Tue Feb 03, 2009 12:19 pm Posts: 914 Location: California, USA
Hi, Folks:
There was a discussion on the use of a trim saw set on a faceting machine in the “Dressing a lap” thread. I have never done that before. Since I use only dop wax for dopping, I did an experiment if wax-dopping can withstand the sawing force.
This is the rough. Slightly ametrine-ish amethyst (38.6 carats).
I picked this rough because it should be fairly large and something I won’t cry, if it is totally ruined.
The saw cutting was loud and messy (lots of splashing swarf). At one time, my spouse came running to see what is wrong. But WOO WHOO! It was fast! I admit I had an Adrenaline rush. After the pre-forming, the faceting time was significantly shorter than my normal time.
Clippings
The recovery wasn’t great: 6.7 carats (17.4%). But now I know wax-dopping is quite strong. Delicate sawing manipulation is another challenge.
Now it is in one of my favorite designs.
Regards,
Mitch
_________________ Best regards, Mitch
I am a slave to cutting a stone completely free of chips and very much enjoying it.
Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
Nothing like sawing, huh? Just remember if you are using wax, that at low temperatures its shock resistance is poor. So make sure your blade is running true so it is not hopping and impacting the stone. Also, the thinner the blade, the faster it cuts. If the stone is reliably held in the dop in a machine, the thin blades work well. Handheld, there is a risk of bending and damaging them. And your fingers.
Joined: Sun Dec 30, 2007 12:01 am Posts: 556 Location: Vancouver, Canada
Congratulations Mitch,
Sure beats faffing around trying to push a chunk of rock through a coarse lap for hours.
Of course you do realise that you aren't in fact saving any time. All of those clippings need to be faceted before you can reveal your 'true' recovery.
This may take you longer than your previous method...grin.
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