Australian opal in striking blues and greens. There is a small area with red and yellow fire. Rough unpolished specimen. Beautiful collection piece or nice material for lapidary work. Opal is 1/8 inch at thickest point on base stone, varying down to a thin "coating".  Some photos and video taken while material was wet, this is a rough unworked chunk of opal on ironstone. Last four photos taken dry. Beautiful color and vibrancy dry. We usually keep it wet in the shop to avoid it getting brittle over time. Approximately 1.25 x 1.25 x 0.5 inches overall specimen size.