The Gold 8-Escudo should weigh 27.0674 grams. A fair example from 1807 weighed
8-Escudo Platinum Counterfeit: 36.5 mm x 1.5 mm; 26.68 Grams in almost uncirculated condition.
Gilded, it should weigh slightly more: 185.95 Grains Gold would be required to weigh true.
A 2-Escudos coin in Gold should weigh 6.7668 grams. This well-worn Platinum counterfeit, presumed contemporary and dated 1805, weighs 6.78 Grams.
This 2-Escudos Platinum forgery, dated 1801 and uncirculated weighs 6.72 Grams.
Assuming a Platinum metal weight of 6.75 Grams, the intrinsic value of a 2-Escudos Platinum forgery on 6/25/2009 was ~USD$ 255.; the numismatic premium was 361%.
The 1801 contemporary counterfeit 2-Escudos (Madrid Mint; FM assayer) Lot 42, Schaumburg Sale 6/25/2009 which sold for $1,092.50
From an 1825 source, von Humboldt describes the appearance of platina in the Mint at Popayan, circa 1809/10. This may reveal a major discovery, an oversupply event, and/or hint that colonial Platinum counterfeits were especially pernicious at that time.
Citation: Annalen der erd, völker- und staatenkunde ..., Vol. 7; Heinrich Karl Wilhelm Berghaus, Karl Friedrich Vollrath Hoffmann, Alexander von Humboldt p. (1826)
After 1810, the price of platina collapsed with the regional anarchy of insurrection, whereby individuals could freely dig and sell the mineral wealth of their lands. Cuoq & Couturier imported large quantity of Spanish platina into France c.1811, and the price of refined Platinum fell by -50%.
Citation: L'Europe et ses Colonies en Decembre 1819, Vol. 1; M. Beaumont de Brivazac (1820) p.219
Citation: Des métaux en France: rapport fait au jury central de l'exposition ... Antoine-Marie Héron de Villefosse, Antoine-Marie Héron de Villefosse (1827) p.52