Weight discrepancy

G'day Stackers, I was just looking on KJC & noticed that a 1 oz gold kangaroo has a weight of 31.107 g
& a 1 oz Platinum kangaroo or Ox has a weight of 31.119 g. Can someone tell me why these 1 oz coins have different weights?
Thanks in advance.

 

One Troy ozt. is 31.1034768 grams , These coins weight are acceptable.

Is how The blanks or rounds being manufactured. They are in different diameter, thickness and density.
This is how to tell which blanks are for what types coins to be made.

 

Thanks Chip. Bugger all difference I know, I just expected they'd be identical weight.

 

Maybe it has to do with the fact that a gold coin is 0.9999 gold and a platinum coin is 0.995 platinum.
So gold has 0.0001 of something else e.g. copper, and platinum has more additional weight of 0.005 of something else.
Just a thought.

 

This will explains better @Shlomo Goldberg

https://www.perthmint.com/education-weights.aspx

 

Thanks SnG & Chip.

 

Good explanation. Thanks.

 

Interesting, perth mint got rid of my blog posts but someone decided a few of the educational ones I wrote were OK but the rest were crap. Oh well.