Maryland Minerals: M to P

This is the third part of  our compendium for the Maryland Minerals website seeking to list all mineral species and varieties of species known to have occurred in  Maryland. As in the previous two portions of that compenium, the  name of any major mineral family and/or group to which a species or variety belongs appears in parenthesis next to the species/variety name. Duly noted on the list also are a relatively few questionable or unverified occurrences.  Also included and similarly noted are the names of  species that the I.M.A. has since discredited. Images of Maryland-collected specimens arranged by county for many of these species can be viewed at the website's  Maryland-collected minerals slideshow.

For nearly all of  information in this compendium, we are grateful to the following sources:

• Minerals of Maryland by Charles Ostrander and Walter E. Price, Jr.,  Natural History Society of Maryland, 1940
• Minerals of the Washington, D.C. Area by Lawrence R. Bernstein, Maryland Geological Survey, 1980
• Smithsonian National Museum of Natural History Database.
• Mindat

Continuing through the end of the alphabet, subsequent posts will cover the names of additional minerals that have been collected in Maryland.

Mackinawite
Magnesioferrite (Member of Spinel Group)
Magnesite

Magnetite (Member of Spinel;Group)
Malachite
Malacolite (rarely used synonym for Diopside)
Manganite
Manganocalcite (synonym for Manganoan Calcite)
Marcasite
Margarite (member of Mica Group)

Marmolite (synonym for both Chrisotile and Lizardite of Serpentine Group)
Meerschaum (German synonym for Sepiolite)
Melaconite (synonum of Tenorite)
Melanterite (principal species of Melanterite Group)
Metatorbernite (Member of Meta-autunite Group)
Mica Family
Microcline  Member of Feldspar Group)
Microlite (Member of Pyrochlore Supergroup)
Millerite
Mizzonite (Synonym  of Marialite, a member of scapolite group)
Molybdenite- First identified in the United States at Jones Falls Quarries
Monazite (member of Monazite Group)
Moonstone (variety of Microcline and sometimes Orthoclase-both members of Feldspar Group)
Moss Agate (variety of Chalcedony, a variety of Quartz)
Mountain Leather (a leathery variety of Asbestos)
Muscovite (member of Mica Group)
Natrolite (member of Zeolite Group)
Niccoline

Niccolite (Italian name for Niccoline)
Nontronite (Member of Smectite Group)
Oligoclase (Member of Feldspar Group)
Olivine (Member of Olivine Group)
Opal
Ophicalcite (same as Ophiolite or Verde Antique)
Orthoclase (Member of Feldspar Group)
Ottrelite (Member of Chloritoid Group)
Owenite (a variety of Antigorite a member of the Serpentine Family)
Paragonite (Member of Mica Group)
Pectolite (a member of the Wollastonite Group)

Pennine (a Variety of Clinochlore)

Phenakite
Phillipsite
Phlogopite (Member of Mica Group)
Picotite (Variety of Hercynite rejected as such by IMA is actually Chromian Hercynite)
Picrolite (Variety of Antigorite, a member of Serpentine Family)
Piedmonite (Member of Epidote Group)
Pigeonite (Member of Pyroxene Group)
Plaglioclase Family (Series member of Feldspar Group)
Platinum
Pleonaste (a variety of Spinel)
Porcellophite (synonym for Antigorite, a member of Serpentine Family
Prochlorite (Synonym of Clinochlore)
Prehnite
Psilomelane (can refer to various  manganese black oxides such as Pyrolusite or Manganite)
Pseudomalachite
Pyrite (Member of Pyrite Group)
Pyrolusite
Pyromorphite
Pyrope (Member of Garnet Group)
Pyrophyllite (Member of Pyrophyllite -Talc Group)
Pyroxene Family
Pyrrhotite
Quartz