Botryoidal aragonite and calcite

Botryoidal aragonite and calciteLocale: Sidi Ayed, Fs Mekns Region, Morocco Approx dimensions: 3 x 2. 5 x 2" Approx size: 365g Calcite and aragonite are polymorphs of one another, meaning that the same chemical composition (calcium carbonate) has crystallized into different crystal structures (trigonal and orthorhombic, respectively). Calcite and aragonite often grow together, and the two minerals are also frequent paramorphs of one anothera pseudomorph of the same chemical

Locale: Sidi Ayed, Fès-Meknès Region, Morocco

Approx dimensions: 3 x 2.5 x 2"

Approx size: 365g

Calcite and aragonite are polymorphs of one another, meaning that the same chemical composition (calcium carbonate) has crystallized into different crystal structures (trigonal and orthorhombic, respectively). Calcite and aragonite often grow together, and the two minerals are also frequent paramorphs of one another—a pseudomorph of the same chemical composition and retaining the original crystal shape but with different crystal structure, created through a change of conditions such as heat or pressure. There is understandably some confusion distinguishing what is calcite, versus aragonite, or a paramorph, or some hodgepodge of all of the above.

Which is all to say, this specimen falls somewhere in that ‘hodgepodge’ category. This piece is mostly botryoidal, meaning composed of small spheres that cover the surface. The spheres are textured and near-opaque with light near-white color. The specimen is attached to a rock matrix with a few small pockets of malachite, which is also commonly sourced from this region.