Natural Stone Analysis

We are specialists in the mineralogical and petrographic investigation of natural stones, rocks and mineral resources by microscopic analysis. Looking for an independent, reliable third-party, analyzing natural stones, rocks and minerals? – J.M.W. Geo-Consulting performs petrographic analysis to evaluate the mineral composition, microstructure and inter-component relationships of natural stones and other building materials, e.g. slates

Principal services:

  • Mineralogical analysis and reporting on ores and industrial minerals
  • Petrographic analysis and reporting on natural stones and rocks
  • Classification and naming of natural stones
  • Petrographic examination according to EN 12407 and EN 12440

Macroscopic classification of natural stones

Macroscopic classification classifies rocks from a macroscopic point of view and uses only a magnifying glass (hand lens) or, if desired, of a stereo microscope. This macroscopic classification is based on the three major groups of rocks:

  • magmatic rocks,
  • metamorphic rocks and
  • sedimentary rocks.

At the macroscopic level, color is also an important criterion in rock classification.

Color is a relatively subjective visual concept that is difficult to determine for heterogeneous, veined and layered rocks.

If the rock shows a sufficiently homogeneous color, we determine it by measurement using the Munsell Rock Color Chart(Geological Society of America, Boulder, Colorado).

During the macroscopic examination, the following properties of the rock are determined:

  • mineralogical composition (macroscopic main minerals only)
  • grain size (coarse, medium, fine)
  • texture
  • macroscopic pores, cracks and holes
  • color (if the rock shows a sufficiently homogeneous color)
  • weathering and alteration
  • presence of macro fossils