Butz said the six "ovens" formed naturally as a result of spherical deposits of quartz eroding out of the phyllite rock face.

WSJ: NY teacher delves into mystery of 'Indian Ovens'

Dr Hazen and his team speculate from meteorite and early rock studies that several hundred mineral species, including zircon, quartz, clay and halite salt crystals, formed during this early period of mineral evolution.

ECONOMIST: Minerals

The smaller eggs offer a choice of materials, techniques and styles such as carved stones and minerals, as varied as rock crystal, chrysoprase, snowflake obsidian, lavender jade, jadeite, pink opal, rutilated quartz, jasper and turquoise.

FORBES: The Miniature Faberg�� Eggs

As the rock that tied them all together, it is fitting that his plaque sits upon on a large white rose quartz boulder.

BBC: An American pilgrimage to Concord