Hopton Wood Limestone
Hopton Wood Limestone can be found quarried near Matlock, in Derbyshire.
Deposited c.330 million years ago in warm, clear, tropical seas during the Visean stage of the Carboniferous.
Typically the "Classic" Hopton wood limestone is a fine, shelly, cream grey limestone with most of the voids filled by recrystallised calcite (biosparite) but varieties comprising a limey mud containing some shelly material (biomicritic) and others with minute pellets set in a microcrystalline matrix (pelsparite) are also relatively common. (Ian A Thomas of The English Stone Forum).
Hopton wood limestone is an entirely attractive stone. It is fine grained and will take a polish, and perhaps a bit harder and denser than Portland limestone.