Ankerite is a mineral that belongs to the carbonate group, with the chemical formula Ca(Fe2+, Mg, Mn)(CO3)2. It is a brownish-red to dark brown mineral that is commonly found in iron ore deposits. There are several synonyms for the word ankerite, including ferroan dolomite, brown-spar, and anchorstone. Ferroan dolomite refers to ankerite that contains a significant amount of iron, while brown-spar is used to describe the mineral's color and texture. Anchorstone, on the other hand, is a lesser-known synonym that is derived from the mineral's ability to anchor or hold together rocks in which it's found. Overall, ankerite and its synonyms are valuable minerals that have practical uses in industries such as construction, manufacturing, and jewelry-making.