Let me just start with: I love this stuff. The weight and solidity, the coolness, the way it takes textures so beautifully. Artistically speaking, cast stone is my favorite. Ever.
That said, the unique qualities of cast stone also make it ideal for tabletop sculpture, so I'm surprised it's not more widely known. Collectors quickly go from curious to delighted when they handle cast stone, though, and for good reason: there's nothing quite like the feel of stone in the hand.
You may not realize it, but you've seen cast stone before
If you've ever wandered past a decorative building facade, you've probably seen stunning examples of highly-detailed cast stone art used in architecture (check out the preservation work done at Balboa Park in San Diego, for example). You can also find the rich history of cast stone sculpture in museums, like this Virgin and Child c. 1395 at the Cleveland Museum of Art, or this Standing Youth, c. 1913, at the Museum of Modern Art in New York.
Different stone serves different purposes
That's not to say all cast stone is the same, though, and I'd wager there are as many ways to approach it as there are artists and artisans. Each artist develops his or her own techniques and preferred materials, depending on their vision. My own approach relies on smooth castings with velvety surface texture and low grittiness, because I intend my work to be handled and enjoyed closely.
Qualities of my preferred cast stone
For my artwork, I seek out materials that are as pleasing to the eye as they are to the hand. I prioritize touch and feel, partially because I'm constantly touching things in my own life (ask my husband - and I'm pretty sure museum staff wince when they see me coming).
I appreciate stone that takes pigmentation and waxes beautifully, allowing for a play of light across the sculpture - and my favorite texture is a silky sheen with lots of depth to the colors.
As one of my collectors so eloquently described the finish of his sculpture, "Turning it this way and that, the light plays over its lines almost musically."
The smooth composite is also what gives the cast stone its velvety texture, which pleases the fingertips. If you're a toucher, like I am, you'll find that the stone is cool to the touch and warms as it's handled, so it feels very responsive.
And while the artists' waxes offer great visual depth, a protective layer of satin varnish allows safe handling without surface damage. I've experimented to find finishes that will last a very long time, even with touchy-feely people like me.
Density and Weight
One reason I've avoided composites with added resins rests in the weight and density of the final sculpture. I prefer pieces with a weight and solidity that almost surprise you, and that reward handling with a satisfying feel. The composite I use gives me that without the addition of common fillers, like lead or sand.
Of course, density also lends itself to greater strength, so the resulting sculpture is more durable and resistant to breakage. So while I wouldn't encourage using your sculpture as a football, you can look forward to many years of pleasure from tabletop or desktop display of your artwork.
The best part is the "ah!" moment
For me, all of these elements come together to allow tiny, expressive details, like cat ears or children's feet, in lasting artwork to be enjoyed for a long time to come. I love to watch people interact with my sculpture, to see their eyes light up, and the hear them laugh, chortle, gasp, and even squeal with glee. For the artist, that's the real gift.