Dollhouse miniature Medium Ballast Iron Ore, 18 cubic inches. Seven realistic colors and three sizes of ballast allow as much accuracy as possible in detailing your layout. We know the importance of the right color for indicating types of track and usage. Also try ballast for wagon loads, roadworks, or gravel bins. Gray Blend Ballast provides the realism of several shades of gray, blended in proper proportions. The larger bag means greater economy.