"In geology, druse, refers to a coating of fine crystals on a rock fracture surface, vein or within a vug or geode.
Druse occurs worldwide; the most common is perhaps quartz druse within voids in chert or agates. Garnet, calcite, dolomitic and a variety of minerals may occur as druse coatings.
Generally, it is possible to find drusy natural gemstones in any location in which there is a place for water to collect and evaporate on rock. It most often appears along river beds and shorelines. It therefore is helpful for collectors, whether commercial or otherwise, to be aware of the minerals common to an area when they look for a particular type of druse." - (en.wikipedia.org 05.10.2020)
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