Lapidaryforum.net
Gadgets, Gizmos, and Dohickeys => Cutting, Grinding, Polishing => Topic started by: landofcrystal on February 13, 2019, 08:36:10 PM
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Hi, just recently got into lapidary. and i have been experiencing issue on quartz polishing. I want to polish raw quartz to showroom shine, like the ones you can purchase from a store. my question is if i have missed a step in order to get to showroom shine? below are steps on how i have been polishing. hope someone here is able to point me into right direction.THX!!
first i use diamond 60 grit to shape and polish out unwanted rough parts. then i use diamond grit 100, then 200, then 600. i often finish up with 1200 or 3000 for final polishing. after that i also use cerium oxide and run quartz on leather pad to give it final touch. then at the end rinse off with water and soup.
here is the problem, quartz does not come out as shiny as were purchased in store, in fact, once quartz dries it does not reflect or shine like mirror. but when i wet it with water, it is crystal shine, am i missing any steps? any help would be appreciated.
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First, Welcome to the forum!
To get a mirror shine on your quartz pieces, you will need to go to a finer grind on the pre-polish, I go up to 14,000 then finish with a good oxide or a much finer diamond polish. I have good luck with a 50,00 diamond paste on a canvas wheel.
I hope this helps.
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What type of equipment are you using , round wheel or flat lap?
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I actually do all these work at my local rock club. I definitely do not recall they have 14000 grit to use for polish. The highest they have is 3000. I mostly use round wheels as flat lap takes way too long. Do you think 3000 would be good for mirror shine ?or is it my technique is not as advanced as other polishers? Thanks
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3000 is often considered fine for agates or jaspers which are much harder than quartz crystal.Quartz crystal material has traditionally been finished with oxide polishes but fine diamond will work if you are careful and thorough. Personally I would go to 8000 then 14,000 and then 50,000 diamond for quartz crystal. Oxides are very aggressive and can make up for fairly bad sanding but they also generate lots of heat and can cause burns or spalling .
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Look at the surface in a strong light sunlight. Preferably with a magnifier or loup. I betting you will see scratches that were not cleaned up with the 600 grit. If so, you will need to go back to 600 and spend more time.