Ca₄(Si,Al)₁₂O₂₄(CO₃)

Meionite is a silicate with a carbonate group. It has the composition Ca₄(Si,Al)₁₂O₂₄(CO₃). The sample at left is about 6x12 cm and is from Minas Gerais, Brazil. These samples are displayed in the Smithsonian Museum of Natural History.

This sample of meionite is about 15x15 and is from La Panchita mine, Ayoquizco, Oaxaca, Mexico. It is characterized as meionite with diopside.

This meionite sample is about 5x9 cm and is from Franklin, New Jersey. It is described as meionite with calcite and amphibole.