5/6/23: The final piece of Obsidian has been taken from this geocache (despite explicit instructions not to take the final rock from any of the caches in this series); there is unfortunately no more Obsidian to see here. You can see pictures of the original contents of this cache, and read more about the rocks, below. Tradeables are now permitted in this geocache.
During the great quarantine clean of 2020, I discovered my rock collection, assembled over years of studying geology in college and just picking up cool rocks along the way. Having way more rocks than we knew what to do with, we thought it would be fun to share them with fellow geocachers in a new series along the Merrimack River: the rock collection! These 15 caches are hidden in a linear fashion along a portion of the Bay Circuit Trail which can be walked or biked, across AVIS's Deer Jump Reservation (and a couple other reservations as well). The containers vary in size, but each should be an easy find. Each one highlights a different really cool rock. Tradeables may not be left in these caches, though if you collect rocks yourself you can keep a rock from some (but not all) of these caches. Coordinates for a possible trailhead are provided, though there are many places you could begin your hike.
Obsidian
Obsidian is a black, shiny rock, a volcanic glass which forms when lava on the earth's surface cools extremely quickly before it can form any sort of crystal matrix. Because of this glassy composition, obsidian can be chipped away at and carved and has been used for centuries to form arrowheads. I found these pieces of obsidian on a thru-hike of the Pacific Cres Trail in Southern California. We had been told by a local that the remains of native american encampments were located just off the trail and if we kept our eyes open for obsidian shards on the trail we could probably find piles of the discarded pieces of old arrowheads. We never found any conclusive evidence that what we had discovered was an ancient encampment... but a lot of the pieces of obsidian that we found do have fractures that seem to suggest carving! As long as there are a few pieces of obsidian left, feel free to take one from the cache if you'd like.
