Re-investigation of the Metamorphic Agates
of the Upper Płóczek, Poland
By: Donald Kasper
· Shows that the amygdules of Ploczek are formed with substantial chlorite chemistry, an indicator of their metamorphic exposure.
· Challenges the view that the prasiolite of Poland is green quartz, and is more likely due to beta-quartz.
· Adds interpretations of many of the specimens lacking in the original text “Agates of the Upper Ploczek, Poland”.
· A number of zoomed in photos of structures not discussed in the original text, are provided and described.
· Shows that some of the amygdules of Ploczek are affected by sericitization, the decomposition of feldspar to make illite clay.
Halloysite (clay) tubes in a sea of agate. Iron adsorption to the clay makes the tubes pink.
From Kaczawskie Mtn., Ploczek, Poland. Photo by Lech Darski.