3.3" Druzy Amethyst "Stalactite" Geode Section - Morocco

The mines near Tarazout, Sidi Rahal, Morocco have produced these very mysterious, beautiful, and rare quartz perimorph geodes for the past 30 years. For many years they were referred to has psuedomorphs or quartz after other minerals, but they are actually perimorphs. Perimorphs differ from pseudomorphs because they do not replace the earlier minerals but rather form a crust on top of them. In this case, quartz/amethyst have grown over an undetermined earlier mineral that has dissolved away.

They are found within a hard basalt, and contain very unique forms which have sometimes earned them the name "stalactitic quartz geodes".

Amethyst is a purple variety of quartz (SiO2) that owes its violet color to natural gamma irradiation, iron impurities, and the presence of trace elements, which result in complex crystal lattice substitutions. It is considered a semi-precious gemstone, and just two centuries ago was considered to have a value on par with diamonds, sapphires, and rubies. The largest and best known amethyst deposits occur in southern Brazil and Uruguay, where they are found in hydrothermally-formed geodes, but many localities around the world produce an amazing variety of amethyst crystals and formations. They are almost always formed in medium- to high-temperature geological settings.

Hematite is a fairly common mineral, typically responsible for the red-brown colorations found in other minerals and rocks. Its chemical composition is Fe2O3, occasionally containing small amounts of titanium (variable formula (Fe,Ti)2O3). Much of the time, non-crystalline hematite specimens are the result of a transformation from limonite following loss of water.