A rare , hard , blue-gray , lustrous transition metal , tantalum is highly corrosion resistant and occurs naturally in the mineral tantalite , always together with the chemically similar niobium .
It is hard and blue-gray .
It is hard and blue-gray .
أعد كتابة الجملة لتكون أبسط: A rare , hard , blue-gray , lustrous transition metal , tantalum is highly corrosion resistant and occurs naturally in the mineral tantalite , always together with the chemically similar niobium . خرج: