January 24 Through February 4—TUCSON, ARIZONA: Annual show
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Thu Mar 28, 2024 6:49 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: Nice to be here
PostPosted: Fri Dec 16, 2016 4:14 am 
Offline
New to the Forum or The Quiet Type

Joined: Thu Dec 15, 2016 6:21 am
Posts: 4
Hello everybody! I'm Kalin from Bulgaria, for 2 years reading and gathering I become a passionate fan of minerals, crystals and gems and build a nice collection. Now I think to move on with my hobby and to try to work with some rough pieces that I have - mostly nice colured agate about 100 kilos and nice amethyst same amount in differnt pieces. I have a friend that can cut them on his machine and I will give a try to sand and polish them. But I want to build my own cabbing machine complete the entire rough-to-polish process, just to order the grinding wheels in different grits. So, I have a question to those who know, how many wheels I need at minimum for a good polish and which grits to choose for agate and amethyst. If I need a fine glass finish, do you recommend using cerium oxide? Anyway any advice will be appreciated wormly!
Thanks in advance
and have a nice weekend!


Top
 Profile  
Reply with quote  
 Post subject: Re: Nice to be here
PostPosted: Fri Dec 16, 2016 4:10 pm 
Offline
Moderator
User avatar

Joined: Mon Apr 02, 2012 9:31 pm
Posts: 4015
Location: North Carolina
Cabbing quartz and agate are very different. Agate is tougher and grinds a bit slower, but also polishes very easily. I usually start with a 180 grit hard sintered wheel for rough shaping (80 grit sintered for very rough shaping in some cases), a 280 soft Nova brand wheel to establish the dome, then a 600, 1200 and 3000 Nova, with an optional 12k or oxide on canvas flat lap for a final polish (60k in rare cases). These numbers look like chipping at the rock with a chisel in comparison to faceting but agates and some other stones are often brightly polished at 3k. Quartz is sometimes more temperamental--some of them will be at a near-final polish at 3k, others will still look a bit hazy even after 12k. I believe a bit of cerium or zirconium oxide on canvas would clear that up, I just haven't gotten around to picking it up yet since I rarely cut macrocrystalline quartz.

_________________
Rough and cut classic and exotic synthetic gems:https://store.turtleshoard.com


Top
 Profile  
Reply with quote  
 Post subject: Re: Nice to be here
PostPosted: Sat Dec 17, 2016 3:27 am 
Offline
New to the Forum or The Quiet Type

Joined: Thu Dec 15, 2016 6:21 am
Posts: 4
Thanks Stephen!
I'll give a try with this grits to see what happen... I have enough material to practise and to learn. The agate is known as Orpheus agate, it has a nice speciffic coloured pattern, and looks cool when polished well.
Anyway, thanks again and have a nice day!


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock