Luxullianite is a rare type of granite, known for presence of clusters of radially arranged acicular tourmaline crystals which are enclosed by phenocrysts of orthoclase and quartz in a matrix of quartz, tourmaline, alkali feldspar, brown mica.
Coquina is a sedimentary rock that is composed either wholly or almost entirely of the transported, abraded, and mechanically-sorted fragments of the shells of molluscs, trilobites, brachiopods, or other invertebrates
From the village of Luxulyan in Cornwall, England, where this variety of granite is found
From Concha (Latin)+ Coquina(Spanish) +conch(English)= Couquina (mid 19th century)
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock