Curious about the world under your feet?

Join with us to explore

the earth's 4000+ minerals and how they came to be!


Mission of the Mineralogical Society of the District of Columbia (MSDC)

  • To learn together and further knowledge about mineralogy and earth sciences
  • To share the pleasure of collecting minerals
  • To welcome you to explore these interests with us

Who We Are

  • We're rockhounds, professional mineral scientists, mineral collectors and enthusiasts, and people with new interests in minerals and earth sciences.
  • We're from DC, the Maryland and Virginia suburbs, and points beyond.
  • You're always welcome!

What we do:

  • Since 1942, we've met at the Smithsonian Institution to discuss all facets of earth sciences and hear  from experts in many related fields.
  • We sponsor or join with other local clubs for field trips.
  • Our monthly newsletters offer diverse articles at all knowledge levels.
  • We support mineral sciences by volunteering at the Smithsonian and elsewhere and by finding other ways to expand interest and knowledge.

When and Where

  • 1st Wednesday of every month except July and August.
  • At the Smithsonian National Museum of Natural History (NMNH), 10th Street and Constitution Avenue NW, Washington, DC.
  • 7:30 p.m. in the Constitution Avenue lobby. A security officer leads us to our meeting room, so please be on time.
  • December time and place may vary.

Great program on Wednesday, May 2! Everyone welcome!

May 2, 2018 Program - Poland’s Treasures:  Amber and Salt

For travelers who are lovers of minerals and gemstones, Poland is a great destination.  Our presenter this month, Denise Nelson, is going to tell us about two of Poland’s treasures – Amber and Salt (mineralogically, Halite).  Denise the president of the Gem, Lapidary and Mineral Society of Washington, D.C., one or our EFMLS sister clubs.  She is a Graduate Gemologist (GIA) and Appraiser.  Denise had the opportunity to take an enjoyable two-week journey to Poland and will share with us some of the interesting parts of that trip that overlap with our areas of interest.


The first of Poland’s treasures that Denise will discuss is a gemstone that is not in fact a mineral.  Amber is fossilized resin (tree sap) that occurs in sedimentary environments.  Strictly speaking, it is a hydrocarbon polymer - organic, not inorganic.  It is created when the buried resin is subjected to high pressure and temperatures produced by overlying sediments, driving off some of the hydrocarbon volatiles and transforming the resin into amber.  This doesn’t happen overnight.  The large quantities of amber found around the coastline of the Baltic Sea, including the coast of Poland, date from 44 million years ago (the Eocene epoch).  Although amber is not a mineral, it is often treated as one in jewelry.  The fossilization process has hardened the fossilized tree resin giving it a Moh’s hardness of 2-2.5, about the same as gypsum.  Despite its relative softness, it can be shaped and polished and used as a gemstone, like the minerals we recognize as precious and semi-precious gemstones.   


The other of Poland’s treasures that Denise will discuss is a place I definitely want to get to one day.  The Wieliczka Salt Mine in Krakow, Poland is featured on Page 434 of a book I own that is titled “501 Must-Visit Destinations”.  The mine has been hosting touring visitors since the mid-1800’s and my destinations book declares it “no less magnificent than the Egyptian pyramids”.  The mine is approximately 1,000 feet deep and is more than 900 years old.  It continues to operate to this day, producing approximately 20 tons of salt each day.  I do not want to say any more about it and steal the thunder from our presenter’s program, except to say that you will be amazed.


Option – Dinner together before meeting


Please join us for dinner with Denise before the club meeting. We will be meeting at 6:00 pm at Elephant & Castle Restaurant, 1201 Pennsylvania Ave, NW, Washington, DC, about 2 blocks from the Smithsonian Institution National Museum of Natural History (NMNH) where our club meeting is held. If you cannot make it to dinner, we will meet in the NMNH lobby at 7:30 pm and head up to the Cathy Kerby Room for Denise’s presentation.


Show and Tell – Anyone have amber or halite minerals?


Since our presentation this month is focused on Poland amber and salt, let’s see what we can come up with related to the presentation.  Amber comes not just from Poland but from a variety of worldwide localities, including Cape Sable, Maryland and Sayreville, New Jersey!  Does anyone have any amber to show us?  Also, salt (NaCl) is known by the mineral name “halite” and is in the halide mineral family.  The halide mineral class includes those minerals with a dominant halide anion (Cl-, Br-, Fl- and I-).  In addition to halite, some of the more attractive halide minerals include atacamite and fluorite.   I know many of us have show-worthy halides in their collection.  Bring them in and let us see them.  Or bring in anything else you want to show us, just because it’s interesting.  If it interests you, it will interest us.


Thanks to Dave Hennessey, MSDC's VP and program chair, for the great write-up above.

Coming soon --

June 6 - Dr. Lance Kearns of the James Madison Geology and Environmental Science Department -- topic not yet announced

Want to know more about any of this?

  • Email us at thompson01 at erols dot com. We’re happy to answer your questions.

  • Check the MSDC newsletter.

  • Visit a meeting any time!