Although small in size, Connecticut is rich in geological diversity. Connecticut formed after a series of orogenies, or island arc collisions, followed by a few million years of rifting, and a couple thousand years of glacial activity for good measure. These events formed the numerous landscapes we currently see in our state, from marble caves in Litchfield County, The Hartford Rift Basin throughout the middle of the state, and the countless North-South oriented drumlins scattered throughout the state. I remember riding in the back seat of my Mom’s minivan as a kid and being mesmerized by the giant outcrops along the side of the highways. My fascination with rocks and the earth led me to pursue a degree in geology. One of my favorite activities is hiking; and while I’m out on a trail or path, I always keep my eye out for any cool and unique minerals, rocks, and rock formations. This hobby has turned into a pretty serious gem and rock collection over the years.

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The Connecticut State mineral is the Almandine Garnet. Garnets can be found in any type of rock; igneous, sedimentary, and metamorphic. For those of you who can’t recall:

Igneous: Cooling magma/lava flows and intrusions.

Sedimentary: Physical and chemical weathering of igneous and metamorphic rocks followed by deposition and diagenesis.

Metamorphic: Transformation of igneous and sedimentary rocks via extreme heat and pressure.

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While garnets can be found almost anywhere, they are often associated with Schists in Connecticut. Schists are metamorphic rocks that used to be shales, sedimentary rocks. Shales consist of clay-sized particles that are deposited mostly in still-water environments. The sediments undergo diagenesis, creating a shale, and then undergo metamorphism due to additional heat and pressure, most likely through burial, to create a schist. This causes the elements within the rock unit to reorganize, if there is enough Aluminum present in the shale then garnets can form.

The presences of garnets throughout Connecticut is no secret, my grandparents would tell me when they were children they would find them along the side of the roads while walking to school. Interest in gemstones and geology in Connecticut led to the creation of the Connecticut Garnet Trail (CGT). The CGT spans from Milford to Stratford, and consists of 10 sites where garnets can be found. These sites are state forests and parks, conservancy land, and privately owned land. I personally have had a lot of luck finding garnets at the Salman River State Forest in Colchester. More information about the CGTcan be found online at the CT DEEP website. Some useful links are:

https://www.depdata.ct.gov/maps/GarnetTrail/index.html#

http://www.ct.gov/deep/lib/deep/gis/garnettrail/ctgarnettrail_all.pdf

Even googling the CGT can yield a lot of great hints and locations for finding garnets in Connecticut. If you are a Gem Hound like me, and this is something that interests you, UConn offers a variety of bedrock and surficial geology maps of the state that can help you find garnets, among other rocks and minerals. Some more useful links are:

http://cteco.uconn.edu/maps/state/Bedrock_Geologic_Map_of_Connecticut.pdf

http://magic.lib.uconn.edu/connecticut_data.html#environmental

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Happy (Gem) Hunting!

-Joe C