• Andrew Scott Johnston, Mercury and the Making of California: Mining, Landscape, and Race, 1840–1890 Series: Mining the American West, University Press of Colorado (September 2013} ISBN 978-1607322429

Mercury mining in California

From : Jimmie Schneider, Quicksilver: The Complete History of Santa Clara County's New Almaden Mine, Zella Schneider Pub (November 1992), hardcover, 178 pages, ISBN 0963457705 ISBN 978-0963457707

When the Nineteenth Century arrived new troubles confronted the Spanish; the ferment of revolution crystallized in the Spanish American colonies. When the New World revolution succeeded, Spain's opulent revenues from the Americas vanished, yet Spain continued as an economic threat by controlling the quicksilver supply. At this point Spain invited bids for a new long-term lease of their Almaden mine and had recently completed a 15,000,000 franc loan from the Rothschilds. Lionel, the son of Nathan Rothschild, appeared in Madrid to enter a bid. With the Almaden mine in their portfolio the Rothschilds also made a deal covering the Idria mine, so the quicksilver monopoly was as tight as ever. In the freshly liberated American colonies, where mining was the chief occupation, the price of quicksilver marched upward with the result that many marginal Western mines went to the wall. The Mexican authorities, realizing that the whole fabric of their economy depended upon this metal, made useless attempts to obtain it on more favorable terms from Spain. Unsuccessful in this, a law was passed in 1843 offering a reward to the first four entrepreneurs who extracted 2,000 quintals of mercury from a Mexican mine. The Junta de Formento was established to encourage prospecting but to no avail, until Andres Castillero found a mountain of cinnabar in California.

During the 14 years that Barron-Forbes operated the mine, including the two years it was closed by a federal injunction, it produced something over 340,000 flasks of quicksilver worth slightly over $18,000,000, of which over half was profit despite all the troubles. Full-scale operations did not get under way until July of 1850 and in this half year 7,723 flasks of quicksilver were produced that sold for prices ranging from $85 to $115 a flask. The first full year, 1851, burning extremely rich ore, production rose to 27,779 flasks and even under a declining market price, with liberal terms for payment, the income exceeded $2,000,000. Barron-Forbes, by judiciously controlling their output, freely supplied all the Hispanic-American and California markets, drove a competitive wedge into the Rothschild monopoly, and allowed prices to decline from $115 to $34 a flask in 1861. This acted as a deterrent to quicksilver prospecting; only two new mines appeared in this decade.