the GNU version of the Collaborative International Dictionary of English
adj. Crystalline on a fine, or microscopic, scale; consisting of fine crystals.
The Century Dictionary and Cyclopedia
Minutely crystalline: said of crystalline rocks of which the constituents are individually so minute that they cannot be distinguished from each other by the naked eye; cryptocrystalline.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. containing crystals that are visible only under a microscope
Word Usage
"I carry a small jar of Vaseline® Petroleum Jelly which is a mixture of mineral oils, paraffin and microcrystalline waxes."