World numismatics records worth mentioning?

[gxseries]

I've been interested in numismatics, mints that have some bragging rights for instance world's largest gold coin, world's first platinum circulating coin, world's first bi-metal, tri-metal etc.

Here's some of my thoughts:

World's largest gold coin record trend: http://lunaticg.blogspot.com.au/2011/11/worlds-biggest-gold-coin.html

World's first platinum coin was officially struck for circulation - Russia 1828 3 ruble

World's first tantalum (bimetal + silver) coin - Kazakhstan 2006 500 tenge

World's first antimony coin - China 1931 Kweichow 10 cash

World's first palladium coin - Sierra Leone 1966, set of 3 coins

World's first titanium coin - Gibraltar 1999 5 pounds

And so on. List can also be the world's most expensive coin of it's catagory. Would like to see interesting records.
 

[Pabitra]

For most expensive coins

See


http://m.siliconindia.com/finance/news/10-Most-Rarest-and-Expensive-Coins-in-the-World-nid-144269.html