(of a material) formed of microscopic crystals.
- ‘This difference is due to the fact that most volcanic rocks are microcrystalline or partly glassy, and thus it is more difficult to classify them by their mineralogical composition.’
- ‘Associated minerals include pyrophyllite, lazulite, quartz, various brightly colored iron oxides, barite, and a suite of microcrystalline phosphates.’
- ‘Finally, the whole surface is protected with a microcrystalline wax containing a corrosion inhibitor.’
- ‘The extent of change, however, varies considerably, depending on the type of microcrystalline stone and on the heat treatment procedures used.’
- ‘The very last fluorite to crystallize left a dusting of microcrystalline snow-white material occupying most of the tight junctures where quartz crystals come together.’