What both states have in common is an abundance of metamorphic and igneous rocks. In fact, geologists sometimes use garnets to gauge how much pressure and temperature a rock has endured. Garnets are a group of similar minerals with the same atomic structure but differing chemical compositions. They are complex silicates, related to quartz . It is unusual for a mineral to be so closely connected with a particular shape, though not all garnets are twelve-sided.
Most garnets are red in color, but they display some variety.
Some are pale, others green. Garnets are quite hard, rating a 7 on the moh scale. Their hardness make garnets valuable as abrasives. Connecticut's history was shaped in part by the mining of garnets, which were used in making grinding wheels, saws, and the super sandpiper known as garnet paper. Connecticut is one of the finest sources in the world of the almandine garnet.