Gypsum may only be 2 on the Moh's Scale, but we also found an appreciation of the work it takes to mine rock. Today I went with the St. Francis Xavier Jr. High to the Alabastine Gypsum Mine for a field trip. The students were then turned loose with their flashlights and hammers in half of the unused part of the mine to collect specimens for half an hour or so. The Alabastine Mining Co. started operations in the early 1800s in the Grand Rapids area. There are six layers of gypsum under the city, and the top layer actually reaches the surface west of town where mining operations started.
Several sources indicate it was the first commercial gypsum mining operation in the United States.
The Alabastine Mine itself was started in the early 1900s when a shaft was dug at the edge of the city to the second layer of gypsum. The ceiling of the mine is dolomite, and it shows ripples, a shoreline at one point, and mud crack impressions. Under the dolomite is a layer of shale and selenite. This gypsum seam runs between six and twenty feet in thickness. More than one student ended up barefoot when their shoes got stuck in the mud and they pulled out of them trying to get free.