Graphic feldspar egg 61mm cut and polished for interior display whether for your abode, home study or office, these mineral eggs make a perfect insight into the worlds mineral growth which has taken place over millions of years. Intermediate compositions of plagioclase feldspar evolve into two feldspars of contrasting composition during the cooling process. The immiscibility gaps in the plagioclase solid solutions are complex compared to the gap in the alkali feldspars and the play of colours visible in some feldspar of labradorite is due to very fine-grained exsolution lamellae.
The name feldspar is given to a group of minerals distinguished by the presence of alumina and silica (SiO2) in their chemistry. It is the single most abundant mineral group on earth accounting for an estimated 60% of exposed rock although to find feldspar of this quality and composition is not easy to find.