This cast was made by filling a seashell with molten aluminum. The shell was embedded in plaster before the aluminum is poured in, just in case the heat of the aluminum cracks the shell. The shell is first sealed with wax to keep the plaster out of the opening and to create a pour spout (sprue). The shell is then cast in plaster. The plaster cast with the shell embedded is then heated to remove moisture and to remove the wax. This is similar to the lost wax casting process. The aluminum is then poured in and allowed to cool. Upon breaking away the plaster and the shell, a near perfect cast of the inside of the shell remains.

Notice that the outer edge of the aluminum cast of the shell is not perfectly curved but appears more like an octagon, with 8 obvious sides per full revolution of the shell cavity. Best seen in the spiral view image. This is from the slight indentions that form the spines that can be seen on the shell. I thought it was interesting that they were so evenly spaced with five every half revolution.

Another cool thing I noticed is that the cast has a solid hole directly through the center which you can see in the spiral view image.

This cast is mounted to a beautiful walnut base. I really got crazy with making interesting shapes for the mushroom cast bases and had this base left over from that project. It's basically a square but with rounded sides. Trust me, it was hard to make! The finish is polyurethane gloss.