melilite, any member of a series of sorosilicate minerals that consist of calcium silicates of aluminum and magnesium; gehlenite is the aluminous end-member and åkermanite the magnesian end-member. First described in 1796 from a sample taken from Capo di Bove, near Rome, Italy, melilites range in colour from white and yellow to brown, gray, and greenish gray. The name of these minerals derives from the Greek words for honey (meli) and stone (lithos). For chemical formulas and detailed physical properties, see mineral: Silicates.
These minerals crystallize from calcium-rich alkaline magmas and from many artificial melts and blast-furnace slags. They are found most often in thermally metamorphosed limestones at contact zones and in impure carbonate rocks altered to feldspathoidal rocks by basic magmas. Melilites also occur in igneous rocks and meteorites.