Quartz striations.

quartz-striationsQuartz striations – Jebel Shams.

An update – these could be hard Calcite crystals given their luminosity: reading a couple of technical papers (see link below) on the geological structure of Jebel Shams would seem to indicate this.
I have limited knowledge on the subject of geology.

A pdf paper from GeoArabia: click the link & click again on the new page for document.
Evolution of fractures in a highly dynamic thermal