Natural Stalagmitic Agate with Cristobalite x 2 From Didi, Madagascar

A NOTE FROM NICK
A pair of natural stalagmitic Agate with Cristobalite formations growing off the surface that you really don't see every day. The combination of the banded Agate base and the wild, contorted Cristobalite habits makes each piece one of a kind.

PRODUCT DESCRIPTION 
Stalagmitic Agate with Cristobalite
Malagasy Stalagmitic Agate with Cristobalite, Stalagmitic Agate forms through the slow deposition of silica-rich fluids within volcanic cavities, building upward in layered concentric banding to produce freestanding stalagmite-like formations with a distinctive ringed cross-section. Cristobalite, a rare high-temperature polymorph of silicon dioxide forming at temperatures above 1470°C, has developed across the surface of these Agate stalagmites in contorted, kinked crystal habits that deviate dramatically from typical prismatic growth. The result is a highly unusual combination specimen the calm, banded regularity of the Agate base contrasted against the erratic, twisted Cristobalite formations above. Madagascar continues to produce some of the most mineralogically surprising combination specimens in the world, and these sit firmly in that category.

ASSOCIATED MINERALS 
Agate, Cristobalite, Quartz

ASSOCIATED FEATURES 
Trigonal, Botryoidal, Drusy, Microcrystalline

ASSOCIATED COLOURS 
White, Grey, Brown, Cream, Clear

MOHS HARDNESS SCALE
6 - 7

PRODUCT DATA
Locality = Didi, Madagascar
Grade = Very Good to A Grade                      
Size = 172 - 184 mm