This is a big and attractive specimen of ¨Dalmatian Stone¨, where a fine crystalline mass of feldspars an quartz, richly spotted by black arfvedsonite clusters. Epidote-group minerals as well as hematite and goethite formed the secondary phases.

According to Powolny & Duman´ska-Słowik (2017), Dalmatian stone is a peralkaline rock. Textural features were not distinctive enough to determine whether the rock had an intrusive or extrusive origin. It may represent peralkaline microgranite or aplite as well as peralkaline rhyolite, since the composition of these rocks may be identical. Alkali amphiboles were represented by anhedral crystals that filled the interstitial spaces between quartz and feldspars. They usually formed radial-like aggregates. Typical pleochroic colors identified the alkali amphiboles as arfvedsonite.

This piece has the frontal face roughly cut by Leendert Weeda (1932-2006). It shows an intense pink fluorescent under long UV.

Combine specimens to reduce shipping costs!.

Tomasz Powolny and Magdalena Duman´ska-Słowik (2017). True Colors of "Dalmatian Jasper", Gems & Gemology, 53 (3). 325-331.