Manhattan is sitting on a treasure trove of minerals and these NY Time writers went in search of them. First stop is Central Park where the mica schist that gives New York’s buildings a strong foundation is visible. Then it’s off to the shores where the material excavated from the construction of subways and skyscraper was piled along the edge of the island. There they find numerous garnets, not excellent quality, but sparkly red just the same, and a bit of black tourmaline. Last stop is the American Museum of Natural History where the New York Mineralogical Club’s impressive collection is housed.