. "Tephroite"@en . "It was first described for an occurrence at the Sterling Hill Mine and Franklin, New Jersey, USA. It occurs in iron-manganese ore deposits and their related skarns. It also occurs in metamorphosed manganese-rich sediments."@en . . "It was first described for an occurrence at the Sterling Hill Mine and Franklin, New Jersey, USA. It occurs in iron-manganese ore deposits and their related skarns. It also occurs in metamorphosed manganese-rich sediments."@en .