Sign in or Register Home
DiamondRing.comYour Online Jewelry Shopping Network
 Ideal Cut Diamond Studs at James Allen 
Buy Sell Education Forum Directory Blog  
View Recent Products View Posts Ask Us Ask our Network Jewelers for a quote on a diamond/gemstone/jewelry




 
Post Reply New Thread
 
Thread Tools Search this Thread
Old Shopsalott

    Shopsalott's Avatar
 
My Profile
Registered User : offline
Joined: 11-20-01
Posts: 353
Years:
 
My Classifieds
Jewelry: 2
 
My Karma
Power: 77
Points: 10
Shopsalott is on a distinguished road


Quote this post and reply to it Post#1 @ 01-14-04 , 08:47 AM


I was watching DSN this morning and saw they had natural color tanzanite. The shades of the stones offered ranged greatly from greenish/brown, green/blue, blue/green, some had a bit of purple. All deep purple/blue tanzanite has been treated , right? I thought I read that tanzanite comes out of the earth brown, but do some have bits of green, blue and or purple naturally? The stones were pretty light in color. Has anyone seen this in person?

Gemstone Search:

Budget:  


Old jewelle

    jewelle's Avatar
 
My Profile
Registered User : offline
Joined: 02-05-02
Posts: 192
Years:
 
My Karma
Power: 74
Points: 24
jewelle is on a distinguished road


Quote this post and reply to it Post#2 @ 01-14-04 , 09:44 AM


I LOVE tanzanite....it's my favorite gemstone !

I've never seen them before treatment. I always heard they were a brownish/green color myself. They never sounded too attractive to me without the heating process. Would be interesting to see.


jewelle signature
~jewelle~
Old Shopsalott

    Shopsalott's Avatar
 
My Profile
Registered User : offline
Joined: 11-20-01
Posts: 353
Years:
 
My Classifieds
Jewelry: 2
 
My Karma
Power: 77
Points: 10
Shopsalott is on a distinguished road


Quote this post and reply to it Post#3 @ 01-14-04 , 09:53 AM


here is some rough natural color I found online:

http://www.mineralminers.com/html/tanmins.stm


Shopsalott signature
Old GemGoddess

    GemGoddess's Avatar
 
My Profile
View profile photo
Diamond : offline
Joined: 03-14-01
Posts: 1,222
Years:
Last seen wearing: my new wedding set
 
My Karma
Power: 91
Points: 362
GemGoddess is just really nice GemGoddess is just really nice GemGoddess is just really nice GemGoddess is just really nice
Hits: Out=3950, In=85
Referrals: 1


Quote this post and reply to it Post#4 @ 01-14-04 , 01:34 PM


tanzanite is the violettish blue variety of zoisite, which in its unheated state is that greenish-brownish. It is POSSIBLE for zoisite to be 'heat-treated' by mother nature, but that isn't what you usually run across. I also don't know of the tests to determine if humans or mother nature did the heating...I don't know that there is one to verify 'natural tanzanite' color...maybe in the big labs. Anyone know?


GemGoddess signature
Stephanie M. Leonard, G.G.
Old metamictman
 
My Profile
Registered User : offline
Joined: 07-13-02
Posts: 108
Years:
 
My Karma
Power: 72
Points: 10
metamictman is on a distinguished road
Hits: Out=512, In=0


Quote this post and reply to it Post#5 @ 01-14-04 , 04:15 PM


Quote:
Originally posted by GemGoddess
tanzanite is the violettish blue variety of zoisite, which in its unheated state is that greenish-brownish. It is POSSIBLE for zoisite to be 'heat-treated' by mother nature, but that isn't what you usually run across. I also don't know of the tests to determine if humans or mother nature did the heating...I don't know that there is one to verify 'natural tanzanite' color...maybe in the big labs. Anyone know?


I don't know about the test either...I doubt anyone's tried to develop one because there's little demand for it.

In its natural state zoisite can be pink (thulite), gray, yellow, brownish, brownish-yellow, colorless and green. Only certain types of zoisite can be heat treated to change color. I have a friend who cut some of the green and called it "Green Tanzanite," and I've seen "Pink Tanzanite" advertised. Both names seem misleading to me because the name "Tanzanite" was originally given to the purple to blue material by Henry Platt, vice president of Tiffany and Co. in honor of Tanzania, the only place it's produced to date. (I keep hearing rumors of tanzanite from Madagascar but can't pin them down).

In its natural state zoisite from Tanzania is grayish to root beer brown. I've heat-treated a fair amount of it and in my experience the darker the brown the more intense and deeper the blue or purple color. Because tanzanite is trichroic (3 different colors when viewed from different directions) crystals can yield either pure sapphire blue cut stones or the more common purplish to violet-blue. That's because the cutting direction for pure blue (considered the most valuable) is usually the direction of lowest yield. Most cutters opt for the higher-yielding purplish hues.

Tanzanite's color can be changed from brown to blue tones by natural sun heat or brushfires, etc. if exposed on the ground's surface. In 1969 a Masai warrior brought a 10,000-carat chunk of transparent purplish-blue tanzanite to a gem buyer in Nairobi. At that time it was a virtually unknown gemstone and the buyer turned it down thinking it was glass. The asking price was $50. Now the disgruntled buyer thinks it might have cut a gem larger than the 220-carat stone now on display at the Smithsonian.


metamictman signature
METAMICTMAN
Old jewelle

    jewelle's Avatar
 
My Profile
Registered User : offline
Joined: 02-05-02
Posts: 192
Years:
 
My Karma
Power: 74
Points: 24
jewelle is on a distinguished road


Quote this post and reply to it Post#6 @ 01-14-04 , 04:24 PM


Quote:
10,000-carat chunk of transparent purplish-blue tanzanite........At that time it was a virtually unknown gemstone and the buyer turned it down thinking it was glass.


I sure wouldn't mind having that "piece of glass" to gaze at........ .


jewelle signature
~jewelle~
Old Sunstone
 
My Profile
Registered User : offline
Joined: 12-12-01
Posts: 26
Years:
 
My Karma
Power: 73
Points: 10
Sunstone is on a distinguished road
Hits: Out=398, In=0


Quote this post and reply to it Post#7 @ 01-20-04 , 08:17 AM


What is DSN? And where can i find the article (if available)?

Thanks!

Last edited by Sunstone : 01-20-04 at 08:19 AM.
Old Shopsalott

    Shopsalott's Avatar
 
My Profile
Registered User : offline
Joined: 11-20-01
Posts: 353
Years:
 
My Classifieds
Jewelry: 2
 
My Karma
Power: 77
Points: 10
Shopsalott is on a distinguished road


Here is the reply I got from mineralminers.com
Quote this post and reply to it Post#8 @ 01-21-04 , 08:50 AM


"Tanzanite is trichroic with brown, blue, and purple colors in different directions, and sometimes one color can predominate over the other two.

We don't heat any of our tanzanite specimens, although the miners
themselves do sometimes heat tanzanite pieces if they think it will
increase the value by removing some or all of the brown color component.

It is safe to guess that tanzanite with no brown color component has
probably been heated."

Sunstone- DSN is a gemstone and jewelry shopping channel on satellite tv.


Shopsalott signature
Last edited by Shopsalott : 01-21-04 at 08:51 AM.
Old phoenix
 
My Profile
Registered User : offline
Joined: 04-16-03
Posts: 151
Years:
Last seen wearing: Nothing at all
 
My Karma
Power: 69
Points: 58
phoenix will become famous soon enough
Hits: Out=0, In=2


rough
Quote this post and reply to it Post#9 @ 01-21-04 , 04:55 PM


I took some pictures of heated and unheated Tanzanite

Attached Images
pict0021.jpg
 
Read Messages in: GEMSTONES All forums
Newer:
Up a Topic Wheres the Garnet by phoenix
Up a Topic Pears weight size posted in JEWELRY by aislingmaire
Older:
Down a Topic Help me find by redraider
Down a Topic To Wedding Consultants posted in Planning a Wedding by 5luckystars
Thread Tools Search this Thread
Search this Thread:
 
Advanced Search

Contact Us - Guidelines - Privacy Policy - Refer a Friend - Top^


Google Custom Search

XHTML | CSS
Logged in as Unregistered
Powered by: vBulletin®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright © 1998 - Present, DiamondRing.com. oHraDaco.
All times are GMT -4. The current time is 03:07 PM.
Validation #23adea8c.