Connemara marble

The parent rock was an impure siliceous dolomitic limestone deposited in a shelf environment on the continental margin of Laurentia.

Minerals formed at this stage were a variety of calc-silicates, including diopside, forsterite, tremolite, together with talc and chlorite.

Subsequent metasomatism, probably associated with hydrothermal fluids from the late Caledonian Galway granites, altered the calc-silicates to minerals of the serpentine subgroup.

[5] As a marble, the most important mineral components are dolomite and calcite, supplemented with variable amounts of diopside, serpentine, tremolite, forsterite, clinochlore, phlogopite, omphacite and talc.

The walls and door frames of the Senate Chamber of the Capitol Building in Harrisburg, Pennsylvania are done in a variety of Irish Jade marble.