Table I

Physical Properties of Seven 3 Rouble Platinum Coins
Year Weight, g Density, g cm−3 Magnetic value* Theoretical Fe content (XRD), wt.% Impurities (XRF), wt.%
1828** 10.351 21.32 0 0 0.7
1832 10.281 20.25 35 2.5 3.5
1835 10.165 20.15 8 0.4 1.8
1836 10.251 20.42 22 1.9 3.5
1837 10.076 20.03 21 1.2 4.1
1838 10.279 20.12 13 0.4 4.1
1842 10.311 20.69 17 1.2 3.1

Density determined by immersion in water. *Magnetic value is the dimensionless reading from the Förster deflectometer calibrated to zero on the 1828 issue. Weight per cent impurities are taken from Table II. **‘Novodel’ issue