Bentorite (Type Locality) w/ Portlandite (both RARE)

Item Description

Bentorite is an ultra-rare hydrated sulfate and is a member of the Ettringite Group. The Hatrurim Formation of Israel is the Type Locality. Portlandite is a rare Ca-hydroxide and is a member of the Brucite Group. Combination specimens are EXTREMELY RARE from Israel. Chromium is the chromophore that causes the pretty lavendar color. All sides of this very rich and colorful blocky piece host bentorite and scattered small lustrous, translucent, tabular plates of pearlescent lustre portlandite. The Hatrurim Formation is largely composed of an unusual rock type, a type of natural portland cement formed by high-temperature alteration of late Cretaceous to lower Eocene bituminous chalk, marl and impure limestone (MINDAT). This is a rich and showy example of this extreme combination rarity. There are no Portlandite photos in the MINDAT Photo Gallery for the locale. Ex Christophe Dubois Collection. I bought one large specimen of this a few years ago, and have not seen more.