▁of ▁official ▁found ry ▁houses ▁( Port ug uese : ▁Cas as ▁de ▁Fund ição ), ▁where ▁the ▁gold ▁extracted ▁received ▁an ▁official ▁stamp ▁required ▁for ▁commercial ▁circul ation . ▁An ▁annual ▁qu ota ▁for ▁gold ▁extra ction ▁was ▁also ▁implemented ▁in ▁order ▁to ▁guarantee ▁a ▁sufficient ▁' qu into ': ▁ 1 , 5 0 0 ▁kil og rams ▁of ▁gold . ▁When ▁the ▁captain cy ▁of ▁a ▁min ing ▁community ▁could ▁not ▁satisfy ▁the ▁royal ▁demand ▁for ▁gold , ▁it ▁was ▁bur den ed ▁with ▁an ▁additional ▁tax ▁on ▁gold , ▁a ▁process ▁called ▁der rama . ▁ ▁The ▁der ram as ▁were ▁made ▁in ▁a ▁general ▁climate ▁of ▁fear ▁and ▁violence . ▁With ▁the ▁de ple tion ▁of ▁several ▁gold ▁mines , ▁especially ▁in ▁V ila ▁Rica ▁( present ▁day ▁O uro ▁Pre to ), ▁the ▁local ▁population ▁lived ▁in ▁fear ▁of ▁an ▁even ▁more ▁violent ▁der rama , ▁which ▁in ▁part ▁triggered ▁a ▁group ▁of ▁" in conf ident es ", ▁consp ir ators ▁against ▁the ▁Portuguese , ▁to ▁start ▁planning ▁a ▁revol t ▁in ▁time ▁for ▁the ▁der rama ▁of ▁ 1 7 8 9 . ▁Notable ▁in conf ident es ▁included ▁L t .- Col onel ▁Francisco ▁de ▁Pa ula ▁Fre ire ▁de ▁And rade ▁and ▁the ▁po ets ▁Cl á udio ▁Manuel ▁da ▁Costa , ▁Tom ás ▁Ant ón io ▁Gonz aga , ▁Al var eng a ▁Pe ix oto ▁and ▁Jo aqu im ▁José ▁da ▁Silva ▁X avier , ▁who ▁would ▁later ▁be ▁best ▁known