Black opaque glass stones rest upon one another in a graded tier. Each stone offering a moment of pause and reflection for the viewer.  

glass, stainless steel base

As seen at Saks Fifth Avenue Flagship stores Worldwide:

3 stone stack : 12"t x 8" w

4 stone stack : 16"t x 8"w

6 stone stack :  20"t x 8" w

8 stone stack:  24"t x 8"w