The Patuxent River Agate


    The Patuxent River Stone is a newly-discovered gemstone that has extraordinary color and has high potential as a gemstone.  It also reflects the geology of Maryland and is found only in Maryland.  Wisps of red and yellow, traces of bone like cell structure, and a glowing translucence make the Patuxent River Agate an excellent stone for cutting, polishing, carving, and setting into jewelry.

    What makes a good state gemstone?

    It should draw attention to something indigenous and beautiful, be interesting and unusual, and bring a sense of pride and identity to a people.        


     A state gem stone should include:

   First of all, the state gem stone should be a native Maryland stone that is beautiful and colorful, and a stone that is tough and will take a fine polish and be able to be fashioned into jewelry.  The stone should be rare but findable, and if the colors are the same as a state flag, this is a plus.  It should occur over a broad geographic area so no one owner controls the source of supply.  It should be able to be collected rather than mined to make it accessible to most people.  Its collection by large numbers of interested prospectors and children should be possible with negligible environmental consequence.  It should encourage interest in the geologic history of the state of Maryland.  It should exist in sufficient quantity to allow for a reasonable source of supply for local artisans.  The Patuxent River Agate meets all of these criteria. 


       The gem is occasionally found in the late Cretaceous gravel of the Arundel formation, which has been mined for decades for construction material.  It is silica replaced fragments of petrified bone material, mostly dinosaur bone, and is evidence of Maryland's roughly 115 million year old bay type environment.  Perhaps 10,000 generations of dinosaurs are represented in the exposed Arundel formation which outcrops though the middle of the state.  The petrification process amounted to infilling of bone marrow by silica and minute amounts of clay.  Perhaps, there may have been some later changes in the crystal structure due to depth of burial.  Recently found specimens prove that there is a link to dinosaur bones.  Many of the internal bone patterns can be readily seen in the cut stones and slabs.  The history of this stone itself is an asset as a gemstone.  The gems can be found best in a narrow band running from Washington D.C. northeast through Baltimore and, thanks to movement by the glaciers, the gems also exist in younger sediments througout the Eastern shore area.  The nature of the formation of these stones may also be connected with the Geothermal hot spots that still exist on the Eastern shore.  We have a number of fine gem, mineral, and Lapidary clubs in Maryland.  It will also be an asset for school study and may touch citizenry at large that are interested in something native to Maryland.  What could be more appropriate for the Bay state than to have a state gem formed on these very lands 115 million years ago when Maryland was also a swampy bay?