150 Roubles Platnum Coin.

There is one thing you must know about Russia, that is, Russia is the only insane country that managed to have circulated platinum coinages back in the years of 1828-1845.

Pardon me, the prices might be right. With 12 of those 150 ruble coins, it's 6 troy ounce and hence multiply that by 1,100USD (around) and yes, around 6,600USD. But yes, prices of such coins have been rising steadily these years. There are both proof and uncirculated platnum coins, and Russia has never ever produced uncirculated platinum coins ever since the 80 Olympics other than the platinum ballerina coins minted in 93 and 94 (if I am not wrong). Ironically, uncirculated platinum coins are actually much rarer, but price wise, is not too much of a difference, although I believe it is set to change.

A platinum 150 ruble coin actually has exactly half troy ounce of platinum, of refineness 0.9995. There are exactly 5 different designs (or 10 different varieties if you want to include both proof and uncirculated) minted from 1977 to 1980, and the last year's design is the "rarest" with its lowest mintage.

This is an example that I have:



1978 Russia 150 platinum ruble. Theme: Discus and the emblem of the Moscow Olympics '80. Nice half ounce proof coin in Pt 9993. Total mintage is 32,356 and only 19,856 of such are in proof condition.

What is more interesting is if she has the whole set in the proper red leather box together with it's original certificates. Such sets are usually bringing over 3 thousand dollars these days.

But I really wonder - such coins aren't cheap in the first place, even though your teacher might have brought them from Russia - those really did cost a fortune in the past.