Log in or Sign up
Coin Talk
Home
Forums
>
Coin Forums
>
Bullion Investing
>
Cause of Red Spots on Gold Coins
>
Reply to Thread
Message:
<p>[QUOTE="GDJMSP, post: 983694, member: 112"]Did you read the first link I provided ? It pretty much contradicts everything you're saying.</p><p><br /></p><p><i>"Amorphous AuxOy compounds have been produced under <u>standard temperature and pressure</u> but decomposed to metallic gold."</i></p><p><i><br /></i></p><p><i>"Of all the metals, gold, chemical symbol Au, has the lowest tendency to react with air to form oxides."</i></p><p><br /></p><p>So gold oxides do exist and they can occur under completely normal conditions.</p><p><br /></p><p><br /></p><p><i>"Structurally, Au2O3, the most stable Au oxide, exists as a square planar compound, exhibiting distorted octahedral geometry coordination on the Au3+ ion and a tetrahedral coordination on the O2- ion. The distorted geometry occurs as a result of d8 orbital splotting, the Jahn-Teller effect. Additionally, radius ratio rules support a distorted octahedral geometry by predicting an octahedral coordination for Au3+ (r = 0.85 A) and a tetrahedral coordination for O2- (r = 1.32 A). [3,5,7] Despite its observed geometry, Au2O3 and other AuxOy compounds exist in an amorphous state."</i></p><p><br /></p><p><i>"One hypothesis that could be made for lower pressure / lower temperature reactions is that the positive slope of the near verticle phase boundary for the stability of the Au metal would decrease to the point that the area of stability of the Au metal would be dominant. By regraphing the data on a ln PO2 vs T plot, a linear relationship would probably be seen with the Au metal area of stability located at the pressure and temperature ranges existing in nature."</i>[/QUOTE]</p><p><br /></p>
[QUOTE="GDJMSP, post: 983694, member: 112"]Did you read the first link I provided ? It pretty much contradicts everything you're saying. [I]"Amorphous AuxOy compounds have been produced under [U]standard temperature and pressure[/U] but decomposed to metallic gold."[/I] [I] "Of all the metals, gold, chemical symbol Au, has the lowest tendency to react with air to form oxides."[/I] So gold oxides do exist and they can occur under completely normal conditions. [I]"Structurally, Au2O3, the most stable Au oxide, exists as a square planar compound, exhibiting distorted octahedral geometry coordination on the Au3+ ion and a tetrahedral coordination on the O2- ion. The distorted geometry occurs as a result of d8 orbital splotting, the Jahn-Teller effect. Additionally, radius ratio rules support a distorted octahedral geometry by predicting an octahedral coordination for Au3+ (r = 0.85 A) and a tetrahedral coordination for O2- (r = 1.32 A). [3,5,7] Despite its observed geometry, Au2O3 and other AuxOy compounds exist in an amorphous state."[/I] [I]"One hypothesis that could be made for lower pressure / lower temperature reactions is that the positive slope of the near verticle phase boundary for the stability of the Au metal would decrease to the point that the area of stability of the Au metal would be dominant. By regraphing the data on a ln PO2 vs T plot, a linear relationship would probably be seen with the Au metal area of stability located at the pressure and temperature ranges existing in nature."[/I][/QUOTE]
Your name or email address:
Do you already have an account?
No, create an account now.
Yes, my password is:
Forgot your password?
Stay logged in
Coin Talk
Home
Forums
>
Coin Forums
>
Bullion Investing
>
Cause of Red Spots on Gold Coins
>
Home
Home
Quick Links
Search Forums
Recent Activity
Recent Posts
Forums
Forums
Quick Links
Search Forums
Recent Posts
Competitions
Competitions
Quick Links
Competition Index
Rules, Terms & Conditions
Gallery
Gallery
Quick Links
Search Media
New Media
Showcase
Showcase
Quick Links
Search Items
Most Active Members
New Items
Directory
Directory
Quick Links
Directory Home
New Listings
Members
Members
Quick Links
Notable Members
Current Visitors
Recent Activity
New Profile Posts
Sponsors
Menu
Search
Search titles only
Posted by Member:
Separate names with a comma.
Newer Than:
Search this thread only
Search this forum only
Display results as threads
Useful Searches
Recent Posts
More...