Wednesday, September 9, 2015

A Major Quartz Crystal Find in Baltimore County,Maryland

During the past year as construction crews were clearing and digging, the now  built over and/or  grown over and off-limits construction site pictured above  near Owings Mills was the site of what could have been the State of Maryland’s most exciting and prolific quartz crystal bonanza ever.  For those with permission to collect and who knew what they were doing, the former construction site yielded notably diverse milky, clear, smoky and amethystine quartz crystal specimens including small clusters and individual crystals, most that were  doubly-terminated, and some with  Cumberland habits as well as a few scepters.

Members of the Chesapeake Gem and Mineral Society, the Baltimore Mineral Society, the Gemcutters Guild of Baltimore, and others  collected  tens  of thousands of quartz crystal specimens. The crystals displayed  by Mark Ruzicka, a Catonsville home improvement contractor pictured with his son Mason and daughter Ashley, bespeak but a fraction of the quantity of specimens they collected in just over a year. Prominent Baltimore County collectors Bob Eberle and Bernie Emery,  the a latter who first informed  Mineral Bliss of the find, collected nearly as many.

Richard Hoff, the immediate Past President of the Chesapeake Gem and Mineral Society, who is pictured at right exploring a crystal pocket, estimates that he collected about 30,000 specimens. Everyone  agrees that the kinds of crystal specimens they fsound changed through different stages of work by an accommodating construction crew.

In the early spring of 2014, the removal of trees from the site uncovered huge quartz boulders bearing numerous milky quartz
crystals. By late spring,  construction crews had removed enough earth to level the entire area, piling the dirt into a mound about 30 yards long,  8 yards wide, and  5 yards high. From these mounds, collectors uncovered plates of quartz bearing multiple crystals measuring to well over an inch. Most of these crystals were milky, some of them clear. Encrustations of dried clay were present on many of the specimens. A different mode of collecting began to evolve around the Fourth of July.

Richard Hoff was there the day that Jim Hooper, President of the Baltimore Mineral Society, wandered a few yards south from the dirt mound and found a single doubly-terminated quartz crystal measuring about an inch and a half. It was embedded in a two foot embankment where a road would later be cut. Almost immediately, Hoff and the other collectors who were present began digging a short distance from the embankment and eventually found more crystals. They dubbed the hole that produced them as “the Hooper pocket.”

In the Hooper pocket and various other holes that struck pay dirt, they typically first encountered small plates of crystals about a foot beneath the surface. As they dug slightly deeper. they found more clustered and individual  crystals.  Some of them hinted at the potential for star patterns as portrayed in the amethystine crystals pictured at left  . Hoff referred to them as “spider legs.” Lots of smokies were in the mix.

Many crystals appeared at first to be floaters. Upon close examination, however, contact points became evident, except where weathered away.  The image at right from a plate of scepter-like crystals provides a hint as to where and how many such crystals could have originated.

The site is near the southwestern edge of a gneiss formation known as the Chattalonee Dome that extends west from Falls Road to about a mile north of Randallstown. In that same area,  a  Johns Hopkins foliation and bedding map of the Chattalonee Dome shows in the general area of the crystal pockets two small patches of fault breccia that is consistent with the micaceous dirt and clay from which the crystals were extracted.  Hoff theorizes that over hundreds of millions of years, both liquid siliceous material and fault breccia filled pockets where feldspar from the Chattalonee Dome gneiss had deteriorated and that crystals began to form that later experienced numerous stages of growth. He suggests that interference from fault breccia material, which also displayed a significant presence of iron (goethite, limonite, and pyrite in specks and tiny crystals) could have accounted for the "spider leg phenomenon. Pictured above at left is one of his less common finds: a golden pyrite cube included within a clear quartz crystal.

Hoff’s  thoughts regarding the science behind these  Owings Mills crystals speak for an innate curiosity and a passion for collecting. Like most who became fascinated with these crystals, he believes that the locality deserves study in academic circles. The opportunity is more than available with the myriad   crystals that Hoff, Ruzicka, and so many others have saved.  Both Hoff and Ruzicka can be reached by email to provide specimens.