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 Post subject: A Fundamental Question from a New Cutter
PostPosted: Sun Feb 21, 2021 4:27 pm 
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Aloha

Here’s a fundamental question: when starting out would you lean more towards cutting quartz to get the hang of cutting, getting points to meet, dopping, etc and not worry about getting a fine polish - or - stick to beryls, zircons garnet etc so you can do everything including getting a good polish?

(I have a Greenway and a BATT lap w 100k diamond syringe currently but am switching to 50k diastik)


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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Sun Feb 21, 2021 9:06 pm 
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I don't get the choice. Are you having trouble getting a good polish on Quartz?


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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Sun Feb 21, 2021 10:06 pm 
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1bwana1 wrote:
I don't get the choice. Are you having trouble getting a good polish on Quartz?

So far yes - I should have mentioned this. I had thought the Greenway would work well for quartz but not so far in my inexperienced hands. It might still just be a prepolish thing. I am going to try phenolic disk with cerium oxide because I have used it before long ago. But I’d love suggestions! :mrgreen:


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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Sun Feb 21, 2021 10:33 pm 
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I would suggest a medium quality garnet if your not very invested in a tool set of laps, but if your lap set allows go for quartz as a low cost somewhat material for practice. Try to select a garnet like pyrope that is not to heavily fractured or included. Garnet polishes quite easily with all most anything. I agree with Steve your question leaves some doubt what your really asking.

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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Mon Feb 22, 2021 12:15 am 
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Thanks for the suggestions. I think garnet is a good choice for me. I’m still trying to find good rough sources since I can’t see anything in person out here.
I tried cutting clean prasiolite and it developed a deep single fracture in the preform. Then I learned that’s not unusual since prasiolite is stressed from heat treatment. I’m currently preforming an ametrine and will try to polish it with cerium. I think in general I’ve been too aggressive with my 260 topper lap and am just using the 600 now.
I used to cut lots of cabs so that might have me being heavy-handed.

Do ametrine, dark orange citrine and “lemon” quartz have this same issue of heat stress?
I have a clean piece of goshenite I might try as well until I get a garnet. Getting a couple zircons too. Really appreciate the help.


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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Mon Feb 22, 2021 2:27 am 
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My advice is that what you learn developing the techniques to get a good polish on quartz is as important as anything you will learn in developing your faceting skills.

Of course we are happy to help you get that down pat.


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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Mon Feb 22, 2021 12:38 pm 
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Good move ditching the 260. Usually, the 600 should be your starting point. Follow that with 3K or 8K for prepolish. Either cerium oxide or zirconium oxide work very well for polishing quartz.

If your current main goal is learning technique, You might consider YAG or one of the high-RI synthetics like Jewelite or Monosital. They can produce beautiful stones and are inexpensive. Your 50K Diastik is a good choice for polish of most anything.


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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Mon Feb 22, 2021 2:24 pm 
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If that 260 is very aggressive and on the newer side, I would only use it to get rid of bulk excess and not use it to cut in facets and using a 600 like a pre polish. Cut in with the 600 and then like Al stated go to 3k or 8k prepolish.

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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Mon Feb 22, 2021 3:19 pm 
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kauai1800 wrote:
Thanks for the suggestions. I think garnet is a good choice for me. I’m still trying to find good rough sources since I can’t see anything in person out here.
I tried cutting clean prasiolite and it developed a deep single fracture in the preform. Then I learned that’s not unusual since prasiolite is stressed from heat treatment. I’m currently preforming an ametrine and will try to polish it with cerium. I think in general I’ve been too aggressive with my 260 topper lap and am just using the 600 now.
I used to cut lots of cabs so that might have me being heavy-handed.

Do ametrine, dark orange citrine and “lemon” quartz have this same issue of heat stress?
I have a clean piece of goshenite I might try as well until I get a garnet. Getting a couple zircons too. Really appreciate the help.

I have never had any issues with quartz and stress by a prior heat treatment, how do you know it was treated?. What dopping technique did you use on the clean Prasiolite?

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 Post subject: Re: A Fundamental Question from a New Cutter
PostPosted: Tue Feb 23, 2021 3:57 am 
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This is all very helpful. I’m currently dopping the flat side with JB Expoxy and am going to use the hybrid wax CA technique on the cone dop. I’m waiting for some green wax. 8)
I think I’m needing more finesse especially on the cutting laps. I haven’t had much chance to simply watch others cutting except on YouTube. I’ll be doing even more careful watching and cutting now.

Tonight I started on a nice AAA Uruguayan amethyst. I plan use 600 to shape the TCP and girdle. Then 1200 (most of the cutting done with 1200), 3000 on one of those plastic sheets, then polish with cerium oxide on a phenolic lap. Does that seem reasonable?


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