chalcocite
...that chalcocite, a profitable and desirable kind of copper ore, was particularly plentiful in the now-depleted copper mines of Cornwall, England and Bristol, Connecticut?
...that <b id="mwAlU"><a href="./Chalcocite" id="mwAlY" rel="mw:WikiLink" title="Chalcocite">chalcocite</a></b>, a profitable and desirable kind of <a href="./Copper" id="mwAlc" rel="mw:WikiLink" title="Copper">copper</a> <a href="./Ore" id="mwAlg" rel="mw:WikiLink" title="Ore">ore</a>, was particularly plentiful in the now-depleted copper mines of <a href="./Cornwall" id="mwAlk" rel="mw:WikiLink" title="Cornwall">Cornwall</a>, <a href="./England" id="mwAlo" rel="mw:WikiLink" title="England">England</a> and <a href="./Bristol,_Connecticut" id="mwAls" rel="mw:WikiLink" title="Bristol, Connecticut">Bristol, Connecticut</a>?