Description

#2342 – A 4 x 3 x 1.5-inch mineral specimen featuring dark blue Lazulite embedded in a grayish-white Quartzite matrix.  This specimen is from Graves Mountain, Lincoln County, Georgia.  The lazulite in quartzite at Graves Mountain originated from hydrothermal activity and subsequent metamorphism of a volcanic tuff deposit that formed about 560 million years ago. Volcanic ash was deposited, and hot, mineral-rich solutions leached elements from the surrounding rock, creating a silica- and aluminum-rich rock. Regional metamorphism, caused by continental collisions around 330–260 million years ago, transformed this rock into the quartzite, kyanite, and other minerals seen today. Lazulite and other minerals like rutile and pyrophyllite then formed in subsequent hydrothermal events after the peak metamorphism.