Hydroxyapophyllite-(K) and Calcite

Item Description

Just 40 minutes away from Washington D.C., this Northern Virginia quarry is well know for its exceptional hydroxyapophyllite crystals. Calcite as an association is very rare, and makes this piece especially beautiful. Studies by Lance Kearns in 2011 determined that much, if not all, of the Northern Virginia apophyllite specimens are uniformly near end-member hydroxyapophyllite and verified its occurrence at Chantilly Quarry. This specimen contains hundreds of transparent, tabular hydroxyapophyllite crystals that look like windowpanes with some amber calcite crystals on a very thin layer of light green prehnite. For how fragile these pieces are, there's a notable lack of damage on a majority of the hydroxyapophyllite crystals. For more information on the Northern Virginia quarries, see the brand new book, "The Northern Virginia Trap Rock Quarries" by the Friends of Mineralogy Virginia Chapter. Ex. Alex Venzke.