Ankerite
（重定向自Bitter spar）
![](/Images/godic/202412/24/Ankérite_Quartz_Pérou4434.jpg")
![Ankerite on pyrite from King County, Washington](/Images/godic/202412/24/Ankerite,_Pyrite_-_Goldmyer_Hot_Springs,_King_Co,_Washington,_USA4434.jpg")
Ankerite is a calcium, iron, magnesium, manganese carbonate mineral of the group of rhombohedral carbonates with formula: Ca(Fe,Mg,Mn)(CO3)2. In composition it is closely related to dolomite, but differs from this in having magnesium replaced by varying amounts of iron(II) and manganese. Forms series with dolomite and kutnohorite.