mineral salt
/ˈmɪn(ə)rəl ˌsɒlt/ /ˈmɪn(ə)r(ə)l ˌsɒlt/ /ˈmɪn(ə)rəl ˌsɔːlt/noun
1A salt obtained by mining, especially rock salt.
2A salt of an inorganic acid.
Origin
Early 17th century; earliest use found in John Pory (bap. 1572, d.?1636), writer and colonial administrator. From mineral + salt.