Polished One Side Agate w/ Pale Amethyst

A polished agate specimen from Cubuk District, Ankara Province, Turkey, this beauty also has some pale amethyst with it! Both agate and quartz (amethyst is a quartz) are two forms of roughly the same thing. Agate is a variety of chalcedony, which in turn is microcrystalline quartz. When we see them together we are seeing environmental changes during different phases of growth. For instance the agate portion likely had faster moving liquid depositing crystal that didn't allow for the time necessary for larger crystals to form. The larger points grew at times when the water moved through in both quantity and with enough time to allow larger quartz. Nifty!