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 denverkris and her Stinking Water Plume Agate Cab!

 www.lapidaryforum.net

Another cabochon contest coming soon!

Pages: [1]   Go Down

Author Topic: Chatoyancy...  (Read 299 times)

0 Members and 1 Guest are viewing this topic.

axllaird

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 54
Chatoyancy...
« on: December 04, 2018, 04:59:21 AM »

Recent outing to the coast revealed a green stone that went from dark to light green and silver as you turned it? Google research showed a similarity to Seraphinite although i'm not sure that would be possible from east coast Scotland? The stone won't scratch with a knife...
DCAM0077.jpg
*DCAM0077.jpg (78 kB . 320x240 - viewed 162 times)
DCAM0076.jpg
*DCAM0076.jpg (78.86 kB . 320x240 - viewed 163 times)
DCAM0080.jpg
*DCAM0080.jpg (83.05 kB . 320x240 - viewed 160 times)
DCAM0082.jpg
*DCAM0082.jpg (89.1 kB . 320x240 - viewed 157 times)
Some other rocks found on the day...
DCAM0027.jpg
*DCAM0027.jpg (97.79 kB . 320x240 - viewed 161 times)
DCAM0028.jpg
*DCAM0028.jpg (67.61 kB . 320x240 - viewed 163 times)
DCAM0030.jpg
*DCAM0030.jpg (76.68 kB . 320x240 - viewed 163 times)
DCAM0031.jpg
*DCAM0031.jpg (96.14 kB . 320x240 - viewed 165 times)

thanks for looking  :occasion14:

Logged


hummingbirdstones

  • Opalholic and General Rock Nut
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2469
    • Hummingbird Stones Lapidary Services
Re: Chatoyancy...
« Reply #1 on: December 04, 2018, 05:43:35 AM »

Wish I could help with an ID, but for sure you can rule out Seraphinite with a Mohs hardness of between 2-4.
Logged
Robin

rocks2dust

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 334
    • rocks2dust items on ebid.net
Re: Chatoyancy...
« Reply #2 on: December 04, 2018, 09:50:13 AM »

To me, it resembles the green mix of serpentine and marble found in the Highlands - it has a name, but cannot recall it.

Another possibility would be a feldspar like labradorite, although I haven't seen a pattern like that. The pattern also isn't something I've seen in prehnite, which I also initially thought as a candidate.

Some of those reds look as if they'd cut nice gems, too!
Logged
r2d

surplus odds and ends that I have on ebid.net
· Xtra gemstones
· Xcess fossils, minerals and rough
· Everything else

axllaird

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 54
Re: Chatoyancy...
« Reply #3 on: December 05, 2018, 02:41:59 PM »

Hi hummingbirdstones and rocks2dust and thanks for the input. The green stone is a puzzle especially with the hardness...hmmm. I had a look at the Iona marble pictures found around the highlands and came across descriptions of good quality stone as green nephrite or Iona Jade...that would be so cool but my stones still looks a little odd compared to the google pics. The little green nodule stone feels pretty light so i'm hoping its hollow when i cut it.
I have found a beach that is absolutely awash with the red jasper you can see in the pictures, there are also greens and oranges there too but in smaller quantities.

Cheers  :occasion14:

Logged

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2454
Re: Chatoyancy...
« Reply #4 on: December 06, 2018, 03:47:37 PM »

We have a sone here that fits the qualifications , enstatite , but yo0u will not find it on the internet except for the pieces I have posted on this forum. The net shows crystalline enstatite but it also comes in a massive form and is green and extremely chatoyant.
Logged

hummingbirdstones

  • Opalholic and General Rock Nut
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2469
    • Hummingbird Stones Lapidary Services
Re: Chatoyancy...
« Reply #5 on: December 06, 2018, 04:19:46 PM »

I knew you'd know what it was, Frank!   :icon_sunny:
Logged
Robin

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2454
Re: Chatoyancy...
« Reply #6 on: December 06, 2018, 07:13:29 PM »

Obviously this is just a guess but there are not a lot of massive chatoyant things out there. Having said that I just cut a 65 lb jade we found in situ  a few years ago and it was wildly chatoyant. I know for sure that this type of enstatite  as well as orthoamphiboles of a different but wild chatoyantcy are found along the coast of Greenland  and glaciers could have moved them  to Scotland. A few years ago we were startled by a geology paper that was able to trace a rare fossil in quartzite  found on my island in Puget Sound to it's  source in Alberta changing the way a lot of people think about  glacial paths.
Logged

hummingbirdstones

  • Opalholic and General Rock Nut
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2469
    • Hummingbird Stones Lapidary Services
Re: Chatoyancy...
« Reply #7 on: December 07, 2018, 05:51:41 AM »

Interesting and it makes perfect sense to me that glaciers could have moved it from Greenland to Scotland.

Sure hope you're going to show a piece of that chatoyant jade for us to drool over!
Logged
Robin

axllaird

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 54
Re: Chatoyancy...
« Reply #8 on: December 07, 2018, 11:50:02 AM »

Thank you lithicbeads i love this forum. Wow it never crossed my mind the possibility of glaciers and a well travelled stone...just when you think you're getting a handle on this a whole new set of possibilities opens up.
I polished a face on one of the stones and it takes a super polish, it looks so good and so strange i was beginning to think it was manmade. I think i'll have a little 'water of life' to help me contemplate  :occasion14:

Thanks again... :hello:
Logged

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2454
Re: Chatoyancy...
« Reply #9 on: December 07, 2018, 06:59:48 PM »

The color of that green stone matches our massive idocrase ( vesuvianite ) perfectly but I have seen many thousands of pieces and have never seen  chatoyantcy.
Logged

rocks2dust

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 334
    • rocks2dust items on ebid.net
Re: Chatoyancy...
« Reply #10 on: December 08, 2018, 11:43:25 AM »

It is nigh impossible that stones in Scotland would be glacial erratics originating in Greenland. For one thing, there is no way anything would be carried across an ocean basin and up the other side (much less across the Mid-Atlantic Ridge). The British Isles also were never connected to Greenland in the past (before Pangea split apart). For isolated deposits near harbors, there is always the possibility of ship ballast being dumped, though the likelihood is very slight that any such rock would have come from Greenland (a Viking wreck?). Occam's Razor would have you look for something similar that is closer to home.

The suggestion of vesuvianite is an interesting possibility. There is some metamorphosed vesuvianite in limestone deposits in Aberdeenshire and Skye, though I haven't seen anything as large or similar in appearance as your pieces from there (just small, brown crystals). Worth considering, however.

I'm also wondering whether what you've described is chatoyancy (a shifting inner glow/line caused by inclusions, lamellae, etc.) or pleochroism (a shift of color depending on how the crystal is oriented)?
Logged
r2d

surplus odds and ends that I have on ebid.net
· Xtra gemstones
· Xcess fossils, minerals and rough
· Everything else

axllaird

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 54
Re: Chatoyancy...
« Reply #11 on: December 09, 2018, 10:18:20 AM »

Hi rocks2dust, i managed to get some outside pics 2day to try and shine a light so to speak. Some great points from your post especially something closer to home and the chatoyant or pleochroism(new for me)question. I don't have the answer unfortunately and may have to make a video.
I had a look on the internet for some time yesterday trying to compare it to something, but maybe its simply a strange variant of a common green stone?
DCAM0090.JPG
*DCAM0090.JPG (89.66 kB . 320x240 - viewed 28 times) DCAM0091.JPG
*DCAM0091.JPG (88.98 kB . 320x240 - viewed 28 times) DCAM0092.JPG
*DCAM0092.JPG (85.39 kB . 320x240 - viewed 28 times) DCAM0094.JPG
*DCAM0094.JPG (91.26 kB . 320x240 - viewed 28 times)
DCAM0096.JPG
*DCAM0096.JPG (82.24 kB . 320x240 - viewed 28 times) DCAM0097.JPG
*DCAM0097.JPG (77.3 kB . 320x240 - viewed 28 times)DCAM0098.JPG
*DCAM0098.JPG (74.12 kB . 320x240 - viewed 29 times)

I also finished a cabochon for a friend from the red material in the pics. It turned out well so i popped out and filled another rucksack yesterday.
DCAM0083.JPG
*DCAM0083.JPG (52.45 kB . 320x240 - viewed 28 times) DCAM0086.JPG
*DCAM0086.JPG (104.7 kB . 320x240 - viewed 28 times)

cheers  :occasion14:




Logged

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2454
Re: Chatoyancy...
« Reply #12 on: December 09, 2018, 10:31:12 AM »

Just to stir the pot- While your piece does not look like nephrite it is known from the Shetland Islands  from a body of ultramafic rocks.Fetlar  and Balta Islands have reportedly hosted nephrite.That is all the info I could find.
Logged

Rustycat

  • Newbie
  • *
  • Offline Offline
  • Posts: 35
Re: Chatoyancy...
« Reply #13 on: December 09, 2018, 10:44:41 AM »

While being abundantly ignorant, my initial thought was Nephrite.  Of course, living on a glacial till I pretty much think I could find almost anything left by the glacier, so I'm assuming similar conditions occur where you are--but, I'm probably wrong. 
Logged
Pages: [1]   Go Up
 

Page created in 0.159 seconds with 53 queries.