Post subject: Re: Selecting a design based off of RI
Posted: Thu Jul 23, 2020 6:07 pm
Site Admin
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Garnet is a group of rock forming minerals many having different optical and physical properties. I was taught (correctly I might add) the hardness of garnet varieties varies from 6.5 to 7.5. Almandine is on the higher end, grossular on the lower.
When I was a teenager, I used to cab everything....in a half ass way. Pink grossular from Asbestos, Quebec and Ant Hill chrome pyrope from Arizona and Garnet Hill in Ely, Nevada.
I always found quartz harder (perhaps as Steve pointed out a better adjective would be tougher with pyrope and almandine) than quartz. But I remember my grossular cutting like butter.
Post subject: Re: Selecting a design based off of RI
Posted: Thu Jul 23, 2020 6:49 pm
Established Member
Joined: Thu Jul 16, 2020 5:17 pm Posts: 44
Stephen Challener wrote:
Better to listen when someone like Barbra (with a degree in geology and a long career of serious gemological work) offers you information.
I mean, it would be pretty ridiculous of me coming in here, asking for information when I'm less than a week into this and then ignoring what people tell me. I want to be clear, I'm not doing that. Just trying to learn. What I'm finding particularly difficult about this as a hobby is that there is apparently information and information out there. You go to one source, and you get one set of information. You go to another source, and you get something completely different. For example, I learned about the Mohs scale in school - but of course I have no experience in which is "tougher" though it makes sense that the shear strength of a mineral may be stronger in some than others...
But that's what I'm trying to sort out here - I've got some time while the other material I'm ordering arrives. Specialized stuff like this always seems to take forever to arrive, and with the current state of the world and the political situation the postal service is in, it seems even longer.
All I was trying to figure out is if there's some additional reason (other than my own sunk time) to not facet that garnet so that I can get some of my own experience under my belt. I'm seeing that with how much fracturing it has, it may explode on me (or I can't anchor it on the dop, or something else entirely) but what's the risk there? Am I going to damage my equipment? Or is it really just my time at risk? I mean, if it's just my time at risk, I see 0 harm so long as I'm just waiting for the mail to arrive....
Post subject: Re: Selecting a design based off of RI
Posted: Thu Jul 23, 2020 7:03 pm
Gold Member
Joined: Thu May 12, 2016 2:18 am Posts: 1542
The biggest risk to your equipment is that the stone comes apart on the lap and microscopic pieces embed in your lap. Then the lap will leave scratches on subsequent stones, so it is basically ruined.
I suggest you start with a variety of natural quartzes to start. Synthetic quartz is harder to polish than natural in my experience.
Az, there is nothing wrong at all with starting with garnet but first you must start with a piece worth faceting. Trying to facet your current piece is a literal waste of time and you will learn nothing about faceting by cutting it. To start with, look up the white paper test though others much prefer placing rough on a mirror. Good, cuttable, garnet is readily available and cheap.
_________________ I just dreamed that I was a butterfly.
Post subject: Re: Selecting a design based off of RI
Posted: Fri Jul 24, 2020 12:02 am
Gold Member
Joined: Tue Apr 05, 2016 7:58 pm Posts: 1424 Location: San Marcos, CA
Believe me you don't want facet this garnet, you will be fine cutting in it and if it crumbles in the process no harm but if you get cut and you go totrying to polish it and it splinters of pieces you will wish you listened. Those fractured pieces are going to contaminate your polish laps. Cutting it for practice is fine but do not try to polish it. I have been here done that and regretted it.
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