France: Platinum Price (Ingot) after 1857

Conflicting reports suggest the French wholesale price for Platinum didn't reach Fr 1,000./kg until 1860.  Other articles citing that same price may refer to retail or manufactures, or an earlier decade.

In the period of Russian coinage (1828-44) the average Russian Mint Price was:
1828-44: 1 Troy Ounce ingot platinum (89% pure ingot)  Fr 36.45-36.00 (USD$ 6.70-7.25)

1857: 1 Troy Ounce (89% pure ingot) = Fr 28 (USD$ 5.47)
1858: 1 Troy Ounce (89% pure ingot) = Fr 26.44 (USD$ 5.08)
1860: 1 Troy Ounce (89% pure ingot) = Fr 31. (USD$ 6.06)

1861-1862?: 1 Troy Ounce (89% pure ingot) rose to Fr. 186.63. (USD$ 36.31)

Citation: Traité de chimie minérale, Volume 5, By Henri Moissan, Marcel Guichard, 1906. p.654


1862: 1 Troy Ounce Platinum  = Fr 29.86  (USD$ 5.76)

Citation: Les Progrès des sciences; Annuaire scientifique, Volume 2 (1863), p.512