Mineralogical characterization of the Shelburne Marble; a Vermont marble test stone used to study the effects of acid rain

The Shelburne Marble of Vermont has been used extensively in buildings and monuments and for this reason has been selected as a test stone for the National Acid Precipitation Assessment Program (NAPAP) stone exposure studies. Mineralogical characterization of fresh Shelburne Marble provides a basis for recognizing mineralogical changes that may occur in samples when they are weathered.

The Royal variety of Shelburne Marble is a white marble with gray streaks of inclusions. It is predominantly composed of calcite (97%) but contains inclusions of dolomite, layer silicates, framework silicates, and non-silicates. The inclusions are heterogeneously distributed in the rock and commonly form linear clusters that are dominated by dolomite + phlogopite + rutile ± chlorite. Less abundant inclusions are: muscovite, talc, quartz, feldspar, pyrite and apatite. All of the minerals that comprise the Shelburne Marble have nearly end-member compositions. Mineral composition, grain size and associations of the inclusions may significantly contribute to the durability (or weakness) of marble used in buildings or monuments that are exposed to conditions of acid precipitation.