65.0 Bedded hematitic aragonite marble. NE Diablo Range, California. The carbonate grains in this marble are aragonite, which appears to be converting to calcite. Cleavages are especially visible in the upper right, but the grain size in the lower part of the sample is clearly aphanitic. Hematite provides the red color. White to gray calcite veins cut across the sample, composed of an upper and a lower bed, separated by a chlorite coated (greenish-gray) bedding plane.