The mineral of the month for May 2008 is Apophylite. This specimen was acquired from a Brazilian dealer who was liquefying his entire inventory at the Tucson show a couple of years ago. He said something about wanting to go fishing. Apophyllite is in the Silicate class of minerals, which tend to be translucent and are lower in specific gravity and harder than most minerals. All silicates contain the silicate atomic structure, whose fundamental building block is the tetrahedron, in which one silicon atom is surrounded by four equally spaced oxygen atoms. Other silicates include quartz, chalcedony, opal, orthoclase feldspar, and amazonite.
Apophyllite is a hydrous calcium potassium fluorsilicate. It can either be colorless or white, gray, green, yellow, or red. It has a hardness of 4 ½ to 5, a specific gravity of 2.3, and has perfect cleavage in one direction. The crystals are tetragonal, usually cube like or tabular and square in cross section. It forms at low temperatures and is commonly found in cavities in basaltic pockets, where it is often associated with zeolites and prehnite. Although this specimen is from Brazil, Apophyllite can be found in the copper mines on the Keweenaw Peninsula among other places world-wide.
The name, Apophyllite, means “to leaf apart” in Greek. The name derived from the tendency of the crystals to peel off when specimens are heated due to the sudden loss of water molecules within the structure. Although collectors refer to this mineral is Apophyllite, it is no longer officially classified as a mineral. Originally, the group name referred to a specific mineral, but was redefined in 1978 to stand for a class of minerals of similar chemical makeup. Apophyllites are popular as with collectors due to their well-defined crystals, color, and abundance.
The metaphysical properties of Apophyllite are thought to enhance your analytical skills and enable you to act in a truthful and honest manner. It can also be used to help you evaluate your behaviors and attitudes so that you can identify and correct any shortcomings.