[x] Welcome at THunting.com!

A fun place to talk about Metal Detecting, Treasure Hunting & Prospecting. Here you can share finds and experience with thousands of members from all over the world

Join us and Register Now - Its FREE & EASY

THunting.com
Treasure Hunting & Metal Detecting Community
   
Advanced Search
*
Welcome, Guest! Please login or register HERE - It is FREE and easy.
Only registered users can post and view images on our message boards.
Did you miss your activation email?

Login with email, password and session length
Or Login Using Social Network Account
2
News:
Pages: 1    Go Down
Print
Share this topic on FacebookShare this topic on Del.icio.usShare this topic on DiggShare this topic on RedditShare this topic on Twitter
Tags:
0 Members and 1 Guest are viewing this topic.
Offline darkkitten2000Topic starter
Bronze Member
*

Join Date: Feb, 2009
Thank you17

Activity
0%

Slovenia
Posts: 150
Referrals: 0

1005.00 Gold
View Inventory

Awards

Miner4 eeTH
« on: March 25, 2009, 05:42:33 am »
Go Up Go Down

Hello,
i came accross two 14 and 18 carat gold alloy rings (modern origin), one quite large, that cannot be detected by PI detectors (tested several commercial and home made ones), and i do not know how the VLFs would do. The conductivity is rather high, much higher then the same size aluminium ring, detected at good 20 cm. The gold alloy is authentic (verified) but the jewellery company wish not to reveal the alloy comosition.
I cannot understand why there is virtualy no eddy currents. Any idea? (It is a well conductive single loop coil, right?)

d.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,4218.msg28022.html#msg28022




Logged
Offline highaltitude
Pull Tab
*

Join Date: Mar, 2009
Thank you0

Activity
0%

United States
Posts: 17
Referrals: 0

110.00 Gold
View Inventory

Awards
« Reply #1 on: March 25, 2009, 06:00:21 pm »
Go Up Go Down

In the NMR field they use alloys of the following materials as coatings to reduce eddy currents in the electromagnets (nickel, iron, cobalt, chromium, molybdenum, copper, and aluminum)  It is possible an alloy of one or some of these metals is either combined in the gold of the ring or coating the ring to help increase surface durability.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,4218.msg28097.html#msg28097




Logged
Offline Homefire
Global Moderator
Platin Member
*****

Join Date: Jan, 2009
Thank you661

Activity
0%
Male
United States
Posts: 15906
Referrals: 0

52360.00 Gold
View Inventory

Awards
« Reply #2 on: March 25, 2009, 08:28:49 pm »
Go Up Go Down

I seen a gold/aluminum ring one time that was way to light to be any gold that I know.

That would be hard to detect.

But at 18K it should be just like any other ring.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,4218.msg28135.html#msg28135




Logged
Offline highaltitude
Pull Tab
*

Join Date: Mar, 2009
Thank you0

Activity
0%

United States
Posts: 17
Referrals: 0

110.00 Gold
View Inventory

Awards
« Reply #3 on: March 25, 2009, 10:41:27 pm »
Go Up Go Down

18K gold contains 18 parts gold and 6 parts of another metal(s), making it 75% gold.

Color of Gold Alloy Composition

Yellow Gold (22K) Gold 91.67%
Silver 5%
Copper 2%
Zinc 1.33%

Red Gold (18K) Gold 75%
Copper 25%

Rose Gold (18K) Gold 75%
Copper 22.25%
Silver 2.75%

Pink Gold (18K) Gold 75%
Copper 20%
Silver 5%

White Gold (18K) Gold 75%
Platinum or Palladium 25%

White Gold (18K) Gold 75%
Palladium 10%
Nickel 10%
Zinc 5%

Gray-White Gold (18K) Gold 75%
Iron 17%
Copper 8%

Soft Green Gold (18K) Gold 75%
Silver 25%

Light Green Gold (18K) Gold 75%
Copper 23%
Cadmium 2%

Green Gold (18K) Gold 75%
Silver 20%
Copper 5%
 
Deep Green Gold (18K) Gold 75%
Silver 15%
Copper 6%
Cadmium 4%
 
Blue-White or Blue Gold (18K) Gold 75%
Iron 25%
 
Purple Gold Gold 80%
Aluminum 20%

There are other less popular alloys.  As you can see 18k gold can be an alloy of many different things.  Rhodium and other exotic metals are plated on white gold for durability and to enhance the white color








Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,4218.msg28147.html#msg28147




« Last Edit: March 25, 2009, 10:47:23 pm by highaltitude »
Logged
Offline Sauerkraut
Copper Member
*

Join Date: Jan, 2009
Thank you0

Activity
0%

Germany
Posts: 64
Referrals: 0

245.00 Gold
View Inventory

Awards
« Reply #4 on: March 26, 2009, 01:32:59 am »
Go Up Go Down

I think all Metals and Alloys must have an eddy Current Effect.
It seems like this Gold ring is outside of the PI sampling Window,
it could be in the "early sampling" Area that is needed for tiny Gold Nuggets
or even in the "late sampling" Area that might be used for Ground Balance.

Use a Scope and take a good look at the PI input Signal after the Clamping Diodes.  Teach


Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,4218.msg28149.html#msg28149




Logged

Extraordinary claims require extraordinary evidence.

Offline darkkitten2000Topic starter
Bronze Member
*

Join Date: Feb, 2009
Thank you17

Activity
0%

Slovenia
Posts: 150
Referrals: 0

1005.00 Gold
View Inventory

Awards

Miner4 eeTH
« Reply #5 on: March 26, 2009, 04:56:15 am »
Go Up Go Down

Clever!


Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,4218.msg28157.html#msg28157




Logged
Print
Pages: 1    Go Up
Jump to:  

Powered by SMF 1.1.19 | SMF © 2005, Simple Machines | Sitemap
Copyright THunting.com