Applying to join this forum, you HAVE to activate your membership in YOUR email in the notice you recieve after completing application process. No activation on your part, no membership.

Lapidaryforum.net

Please login or register.

Login with username, password and session length
Advanced search  

News:

Welcome new members & old from the Lapidary/Gemstone Community Forum. Please join up. You will be approved after spam check & you must manually activate your acct with the link in your email

Congratulations to Bobby1 and his Brazilian Agate Cab!

 www.lapidaryforum.net

Another cabochon contest coming soon!

Pages: [1]   Go Down

Author Topic: Common opal slabs  (Read 146 times)

0 Members and 1 Guest are viewing this topic.

VegasJames

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 430
Common opal slabs
« on: October 19, 2021, 12:34:37 AM »

002 by James Sloane, on Flickr

003 by James Sloane, on Flickr

004 by James Sloane, on Flickr

1005 by James Sloane, on Flickr

1006 by James Sloane, on Flickr

1007 by James Sloane, on Flickr

1008 by James Sloane, on Flickr

1009 by James Sloane, on Flickr

1010 by James Sloane, on Flickr

1011 by James Sloane, on Flickr
Logged

peruano

  • Retired Zoologist
  • Sr. Member
  • ****
  • Online Online
  • Posts: 373
Re: Common opal slabs
« Reply #1 on: October 19, 2021, 04:06:05 AM »

Nice colors. I'm guessing that this material likes to chip when you are cabbing it. I can see  lots of fractures exist.  Fun to work with when successful I'll bet. 
Logged
Combining a love of bikes (pedal and otherwise) with hiking, hounding, lapidary, and the great outdoors

VegasJames

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 430
Re: Common opal slabs
« Reply #2 on: October 19, 2021, 09:13:33 AM »

Have not had a problem with chipping, but it does fracture. So I generally break the slabs along their fractures first then cab the pieces that remain. Yes, it great and easy to work with.

Opal cabs 2 by James Sloane, on Flickr

118882052_3422885837769714_4167399160304763993_o by James Sloane, on Flickr
Logged

vitzitziltecpatl

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1004
Re: Common opal slabs
« Reply #3 on: October 19, 2021, 05:21:31 PM »

Wow - VERY nice cabs from your rough.

It is much better to whack them on the table (our method) to find the solid bits, eh?

Some people miss out on good stones because they see fractures in the rough. St. Johns Flower Agate that is like that. It's a little extra work to "cut between the cracks" - but it's worth it. Just like your opal. That's great stuff.

VegasJames

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 430
Re: Common opal slabs
« Reply #4 on: October 19, 2021, 09:25:36 PM »

Wow - VERY nice cabs from your rough.

It is much better to whack them on the table (our method) to find the solid bits, eh?

Some people miss out on good stones because they see fractures in the rough. St. Johns Flower Agate that is like that. It's a little extra work to "cut between the cracks" - but it's worth it. Just like your opal. That's great stuff.

I don't whack them with hammers because I do not want to make more cracks. I just slab the material and see what I have. If the piece is too unstable I throw it in the tumbler with other opal for a week. Then I can use the pieces for various other projects.
Logged

vitzitziltecpatl

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1004
Re: Common opal slabs
« Reply #5 on: October 20, 2021, 07:03:25 AM »

Hiya' James!

Sorry if I wasn't as clear as I should have been. We do not bash chunks - or anything else - with hammers.

Raising one end of a slab an inch or so above a tabletop and then smacking it down evenly on the table is good, though. If a slab already has obvious fractures it will probably also have less visible ones, too. This will usually "find" them.

One other (less violent) way we find them is to dunk them in water and then wipe the surface off. The fracture lines that can hold water will be visible for a short time after the rest of the surface has dried.

I'm sure you have heard of these methods, but others newer to the lapidary world might benefit from having them posted here.

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2995
Re: Common opal slabs
« Reply #6 on: October 20, 2021, 06:26:18 PM »

Here in Washington the cpommon opal beds often have agate nodules in them as a quite  small percentage of the deposit. The deposits have and are mined giving big head walls to sample the layering on a grand scale.
Logged

VegasJames

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 430
Re: Common opal slabs
« Reply #7 on: October 20, 2021, 07:02:24 PM »

Here in Washington the cpommon opal beds often have agate nodules in them as a quite  small percentage of the deposit. The deposits have and are mined giving big head walls to sample the layering on a grand scale.

The dehydration product of opal is chalcedonies such as agate, jasper and chert/flint. So they do often occur together.
Logged

Felicia

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 488
Re: Common opal slabs
« Reply #8 on: October 21, 2021, 08:58:28 AM »

Looks like some super handsome  looking cabs in your future!
Logged

peruano

  • Retired Zoologist
  • Sr. Member
  • ****
  • Online Online
  • Posts: 373
Re: Common opal slabs
« Reply #9 on: October 21, 2021, 02:59:45 PM »

You have not used the word "wood" in this thread but to my eye some of these slabs closely resemble opalized wood.  I have collected one locality extensively here in central New Mexico and my material is distinct in color but has patterns that resemble the Nevada material.  What do you think?
Logged
Combining a love of bikes (pedal and otherwise) with hiking, hounding, lapidary, and the great outdoors

VegasJames

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 430
Re: Common opal slabs
« Reply #10 on: October 21, 2021, 03:10:35 PM »

Yes, all of it opalized wood from Nevada.
Logged
Pages: [1]   Go Up
 

Page created in 0.08 seconds with 43 queries.