Both the Limestone and the sandstone fall into the "Medium-Density" category as defined by the ASTM definitions.
Stone Stats: (medium-density as defined by ASTM):
Abrasion Resistance, min. hardness: 10
Max. Absorption Rate (%): 7.5
Min. Density (pcf): 135
Compressive Strength (psi): 4,000
Modulus of Rupture (psi): 1,000 (min)
Related Garden Design, Ornaments products from this supplier