A rather large, deeply colored calcite from the Berry Materials Quarry in Indiana.  The American Midwest is home to numerous quarries that produce everything from frac sand to food grade lime.  Many of these locations also happen to produce interesting calcites, and the habits often vary substantially from quarry to quarry.  Perhaps the most distinctive (and certainly my favorite) are the examples from the Berry Materials Quarry-- they tend to be a bit more rounded in appearance, have better color, and are often quite lustrous.  This one is a bit larger (and also more elongated than most) and is a particularly nice example.