Single crystals of Natrolite that are capped by Mesolite in cavities can be found in the Columbia River Basalt group near Clarkston, Washington. Chemical tests on both these crystals showed that they have near identical compositions. The summary of this article states that Natrolite can turn into Mesolite if the Petro-genetic conditions are right. They most likely change during crystal growth and certain minerals may hold the key, such as Calcite. \cite{gtinter1993composite}