2 SEM images of gemstones: emerald and ruby (Electron Miscroscope with Secondary Electron detector, (which "takes picture" of surface layer (~0.5 um) both the elemental composition and relief)). Dendrites - it is clear (not me, but in general), what creates other patterns? * trace elements? - the stones are very clean (<1000 ppm) and well processed * relief? - OK and next question: why such relief? * electrostatics? - definitely not. Electrostatics in dielectrics looks like distortion at the top of ruby photo. * anything else? I would be very grateful for any ideas! Or any links.