In 1835, during the First Carlist War, the mine was leased indefinitely to the Rothschild Bank. The price paid was high, but one of the Rothschild family firms had previously purchased the quicksilver mine in Idrija (now in Slovenia) from Austria; thus the firm had a monopoly on quicksilver (until discovery of New Almaden in California). Volume was expanded and the metal sold at a substantial markup returning a substantial profit to both Spain and the firm. Spain reclaimed the mine in 1863.