BLUESTONE VARI 1" STANDUP 1" Bluestone Variegated Natural Cleft Standup Field can be very versatile and can be ordered in a variety of widths, thicknesses and surface textures. Typically comes in a blue-gray color but it is also available in a variety of colors that includes more earthy tones. Natural cleft bluestone is a bluestone that has been split or cleft into layers during the quarrying process.