It is with great sadness I'd like to announce Dr. Hanneman passed away on December 12, 2020. His legacy will live on forever!
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Sun Jan 17, 2021 11:51 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 82 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next
Author Message
 Post subject: Re: My Mexican Amber article
PostPosted: Sat Jun 22, 2013 11:50 am 
Offline
Established Member

Joined: Sun Mar 13, 2011 10:36 am
Posts: 35
Location: Canada
Merci Danielle, but back to the Chiapas amber i still prefer the reds.
I don't know if its just my camera but they are much more vivid "in the flesh."

Lighting is indoor regular incandescent.
Regards/Yeti


Attachments:
flytrap.jpg
flytrap.jpg [ 132.79 KiB | Viewed 3978 times ]
chiapas reds2.jpg
chiapas reds2.jpg [ 162.15 KiB | Viewed 3978 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Sat Jun 22, 2013 5:30 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Wed Dec 16, 2009 5:03 am
Posts: 787
Location: Paris
Thanks , yeti :)
The first piece is wonderful , I love it :smt007

_________________
danielle

"I always believed in being myself"- Thelonious Monk


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Thu Jun 27, 2013 7:31 pm 
Offline
Valued Contributor

Joined: Sat Jul 07, 2007 8:06 am
Posts: 418
Location: uk
Hi Yeti the amber looks good , how was it to work with the blue ,is it stable? it seems its not highly oxidized then like alot of red amber, that is likely to fracture break or even crumbie.
I have not worked with blue amber. Back in the late 1990s someone had a few kilos
It was in Simojovel. I did not buy thinking maybe the fluorescence blue was just on the surface, and would be lost in the sanding

_________________
http://www.mexicanamber.org.uk


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Fri Jun 28, 2013 10:08 am 
Offline
Established Member

Joined: Sun Mar 13, 2011 10:36 am
Posts: 35
Location: Canada
Dave, the Indonesian amber seems to be more copal than amber, it gums up when cutting, prone to breaking and doesn't polish as nicely as chiapas or baltic. The colour varies widely from a murky chocolate to a cloudy clear and is consistent under the surface making it quite difficult to search for inclusions.

JMHO, i'm still a nubie when it comes to this stuff.

Yeti


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Sat Jun 29, 2013 2:57 pm 
Offline
Established Member

Joined: Sun Mar 13, 2011 10:36 am
Posts: 35
Location: Canada
Having said all that (my rant for the week) i have another installment of "Fun with Light" for your perusal and edification...pic 1 shows natural light with a black background. pic 2 shows natural light with a white background. pic 3 shown with white led backlight illustrating the red inclusion flow interspersed with the clearer amber.

So what is it...red, white, or blue amber? Your call.

This indonesian amber is from the Kalimantan coal fields.

Regards
Yeti


Attachments:
borneo blue.jpg
borneo blue.jpg [ 185.51 KiB | Viewed 3894 times ]
borneo blue2.jpg
borneo blue2.jpg [ 71.05 KiB | Viewed 3894 times ]
borneo blue3.jpg
borneo blue3.jpg [ 105.41 KiB | Viewed 3894 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Wed Jul 10, 2013 9:20 am 
Offline
Valued Contributor

Joined: Sat Jul 07, 2007 8:06 am
Posts: 418
Location: uk
Hi Yeti Lots of fluorescence colores in your amber
Not much information to be found on indonesion amber
On the web no scientific papers at all on it. Sue Aber Ward as the resin coming
from a tree in the family Dipterocarpaceae. the same family of tree which as produced the new found amber deposits in Gujarat India
Its interesting that this family of tree is still dominant in north Borneo
Do not know how much of this amber from Gujarat is gem quality Though it is said to be about 50 million year old, alot of it is not fully fossilized & still is copal or in a state between amber & copal
Yeti You found any interesting inclusion in the Indonesion amber

_________________
http://www.mexicanamber.org.uk


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Fri Jul 12, 2013 6:14 am 
Offline
Gold Member

Joined: Wed Jan 23, 2013 5:29 pm
Posts: 1047
Location: Paris
I have found 2 weeks ago in Sainte-Marie aux Mines a piece (55 carats) of blue amber from Kalimantan which left me jaw-dropping. The deep blue fluorescence is really impressive and much stronger than any of the blue domenican amber which I have seen so far (and I have seen and brought back from there really nice samples). You don't need any particular lighting to get the blue effect, even under dim sunshine the piece looks very blue. Under LED lights it is just uniform navy blue. Beautiful... and cheap.

The piece is just polished, translucent but rather cloudy, as Yeti says, and the polish is not so good, with a sticky feeling under the fingers. I'll try to see if I can improve the polish.

I haven't tested it yet with acetone or alcohol. I understand that the Kalimantan blue amber (or copal) is a recent find, is it why you cannot find much information about it ?


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Wed Jul 17, 2013 3:11 pm 
Offline
Valued Contributor

Joined: Sat Jul 07, 2007 8:06 am
Posts: 418
Location: uk
Hi Isi How did You get on polishing the amber
In Mexico after fine sanding with a well worn 1200 or 1600 grit sanding paper
hand polishing it is on polystyrene using brasso metal polish, it works well
lot of interest from scientists in the inclusion in the amber from Gujarat India as it comes from a time 50 million years ago when India was still not connected to Asia
Strange can not find any information on the inclusions in amber from Indonesia

_________________
http://www.mexicanamber.org.uk


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Wed Jul 17, 2013 3:23 pm 
Offline
Gold Member

Joined: Wed Jan 23, 2013 5:29 pm
Posts: 1047
Location: Paris
As for the polishing I'll keep you updated within a few days. I don't have the necessary tools myself, I'll just bring the piece to a good friend of mine, lapidary, who has all sorts of grinding wheels... But is currently on holiday.

I've tested the piece with acetone and alcohol. Both solvents left the surface absolutely undamaged. The luster seems to be even improved ; probably it had a cleansing effect.

There is a strange inclusion inside, like a kind of big leaf curled upon itself, with much oxidation ; hard to describe. Otherwise the stuff is clear, brownish yellow in transmitted light.


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Wed Jul 24, 2013 1:09 pm 
Offline
Established Member

Joined: Sun Mar 13, 2011 10:36 am
Posts: 35
Location: Canada
Welcome to the chat Isi...the blue is indeed a very rich colour, quite different.

you said..."probably it had a cleansing effect"

Heres my theory on that, i think the original resin is a very clear substance similar to chiapas based on some chips i broke off and anything else in the above samples are possible inclusions (by definition) of a swampwater mix that occurred as the resin settled in the prehistoric peat bog/swamp that eons later became the Kalimantan coalfield. (just guessing at this.)

That might explain the reddish inclusive (white LED) flow throughout some samples and also possibly explain the surface texture that is very slightly tacky, it also could explain the gumming up under a tool unless worked at much lower speeds than Chiapas or Baltic. I think the actual resin has turned to amber alright and when cleaned with acetone, any surface oily bits are dissolved, leaving a fresh glossy surface.

What i don't quite get is a few days later i go back and recheck the sample, it's not quite as glossy (to the touch) anymore... its almost as if the minescule oily bits have migrated to the surface again...i guess a microscope and a chemical analysis of the specific red pigments may help with this.

No insect inclusions so far Dave.

regards/yeti


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Thu Jul 25, 2013 4:55 am 
Offline
Gold Member

Joined: Wed Jan 23, 2013 5:29 pm
Posts: 1047
Location: Paris
Very interesting, Yeti.

Actually under the binocular I could see the small reddish dots you talk about, surrounding the oxidised included area.

I look forward to having my piece neatly repolished, so that I can check afterwards if the sticky feeling comes back.

I find it a pity that the material is turbid in look and that the high polish cannot be retained ; otherwise, with its amazing blue fluorescence, this amber might become a big sensation among organic gems !


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Mon Sep 02, 2013 2:30 pm 
Offline
Gold Member

Joined: Wed Jan 23, 2013 5:29 pm
Posts: 1047
Location: Paris
I eventually had my blue amber repolished. The surface is really improved but still it seems impossible to get rid of the slightly sticky, elastic touch. I could not obtain a glossy, shiny polish like that of other types of amber (baltic, burmese, mexican, domenican).


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Wed Sep 11, 2013 10:50 am 
Offline
Gold Member

Joined: Wed Jan 23, 2013 5:29 pm
Posts: 1047
Location: Paris
Hi all,
I confirm Yeti's observation : a few days after repolishing, the surface of my indonesian blue amber seems again to be sticky and slightly greasy as before. As if some fluids from inside had seeped through anew. Very odd indeed !


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Mon Nov 04, 2013 10:44 pm 
Offline
New to the Forum or The Quiet Type

Joined: Sun Nov 03, 2013 10:02 pm
Posts: 6
"Dave, the Indonesian amber seems to be more copal than amber, it gums up when cutting, prone to breaking and doesn't polish as nicely as chiapas or baltic. The colour varies widely from a murky chocolate to a cloudy clear and is consistent under the surface making it quite difficult to search for inclusions.
JMHO, i'm still a nubie when it comes to this stuff.
Yeti"

Hi Yeti,
You are probably right, Indonesian amber it's definetely more copal than amber, besides guming and not polishing well,it's waxy in appearance and oxidises very quickly, loosing its blue hues,the blues and greens fluorescence in copal and amber do not disappear when sanding, it's rather the oxidation that inhibits the fluorescence, when polishing again, the amber and copals will show the blues or greens again.


Top
 Profile  
Reply with quote  
 Post subject: Re: My Mexican Amber article
PostPosted: Tue Nov 05, 2013 5:57 am 
Offline
Gold Member

Joined: Wed Jan 23, 2013 5:29 pm
Posts: 1047
Location: Paris
Hello Gemart
If indonesian stuff is more copal than amber, how is it that it seems to be undamaged by solvents such as alcohol and acetone ?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 82 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 1 guest


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