polyadelphiteMin.|ˌpɒlɪəˈdɛlfaɪt| [f. as prec. + -ite1: so named as consisting of five different silicates united.] A massive brownish-yellow variety of iron garnet, found in New Jersey. 1836T. Thomson Min. I. 154 Polyadelphite..was sent me by Mr. Nuttall.1892Dana Min. (ed. 6) 443.