Definition of penfieldite in English:
penfieldite
noun
Mineralogy
A rare mineral of the hexagonal system which consists of a basic lead chloride, Pb₂Cl₃OH, and typically occurs as tiny prisms, colourless when pure.
Origin
Late 19th century. From the name of Samuel L. Penfield, U.S. mineralogist + -ite.
Pronunciation
penfieldite
/ˈpɛnfiːldʌɪt/