Serpentines
Serpentine's a metamorphic rock abundant at the boundary between the base of the oceanic crust and the upper mantle, so groups are (a.) rarely at the Earth’s surface and (b.) abundant at the “oceanic Mohorovicic discontinuity”. Olivine minerals are replaced by various minerals of serpentine by a process called “hydrothermal metamorphism” in the presence of seawater. Olivine has a composition of Mg2SiO4 and Fe2SiO4. Olivine also has the general formula (X)2SiO4 refers to an X variable of Mg, Ca, Ni, Mn, or Fe. Because serpentine best describes a group of minerals, its general formula is as follows: (X)2(Y)2O5(OH)4 or (X)3(Y)2O5(OH)4 The X variable may be Mg, Fe, Ni, Mn, or Zn, while the Y variable may be Si, Al, Fe. Since serpentine minerals are rare, when they are found, the rock is composed of mixtures. The term “serpentines” refers to fine-grained inclusions giving a freckled look to the minerals. Much of the Earth's surface is said to be underlain by serpentines, since they form underground at the “convergent plate boundary” where the crust is pushed by gravity into the Earth’s mantle. When remnants of the ocean plates are exposed at the surface, the remnant results from either uplift-weathering or fault-thrusting — the later process exposing the present-day plate.
Beliefs in the healing virtues of serpentines obviously originated from semantic ideas regarding its name. Its use as an amulet has its origins from ancient Egypt however, while its use in magic becomes unclear as one’s research goes further back in time. Civilizations of Mexico used serpentine as a substitute for jade. Georgius Agricola named serpentine in 1564 from the Latin for “snake” according to its freckled green appearance. Other than serpentine's green color and its slippery feel, what appeared as reptilian scales was how its name came into being. Italian peasants thought that by placing a serpentine rock on a snake bite it, acting like an amulet, would draw-out the venom. Architectural designers used serpentine in the 20th century as marble, yet the mineral has since fallen to disfavor. Ironically, scientists today have found them capable of absorbing carbon dioxide. The “slippery feel” of serpentine is a diagnostic property. Black serpentine was popular in antiquity for cuneiform cylinders — the earliest examples depicting animals rather than writing can be dated to before 2500 BC. Serpentine was used in ancient Egypt for engraving Ch.30 from the Book of the Dead, referencing the heart.
“Formula for not allowing the heart of N to be removed from him
My heart of my mother, my heart of my mother, my heart of my earthly being
Do not stand against me as witness beside the lords of the ritual
Do not say against me, he did do it, about my actions
Do not make a case against me beside the great god
Hail my heart, Hail my heart
Hail my entrails, Hail those gods
At the fore, tressed, resting upon their scepters
Tell my goddess to Ra, hand me to Nehebkau
See him, uniting the earth and the great one within
May I endure on earth, not die in the west, and be a blessed spirit there”
Not until after 300 BC did flattened rings made of minerals including serpentine begin to emerge. The above passage known as the Heart Scarab Spell came from a 1250 BC document written by Ani, a Theban scribe. A scarab shaped amulet inscribed with the heart spell would be placed over the decedent’s heart. This burial practice continued until the third century BC. The ancient Egyptians did not have a particular mineral specific word for its green-black serpentine used in crafting although one may suspect it was confused with jadeite.
Lime green, translucent specimens of serpentine carved into cabochons are considered rare and known as Williamsite originally mined at the State Line Chrome Mine in Pennsylvania. Williamsite was so named in 1848 by Charles Uphem Shepard (1804-1886), mineralogist, in honor of Lewis White Williams (1804-1873), geologist and mineralogist. Because it's a minor gemstone without a consistent durability, Williamsite will be infrequently used for jewelry since it's unable to withstand regular wear. Chalcedony makes a suitable replacement provided the Williamsite is opaque. Both green, chrome chalcedony and Williamsite (itself green) may be used interchangeably although the translucent variety of the two can be more valuable. Interestingly, a crystal of Williamsite forms directly by metamorphism of the two olivines (mentioned before). The chemical nomenclature for the resultant is the following: magnesium iron silicate hydroxide plus chrome. It forms a monoclinic crystal system. The additional component being where it gets its jade-green color. According to National Labs, it has been used as a “jade simulant” even though it frequently contains magnetite inclusions.
Since its discovery, Williamsite serpentine has been given several metaphysical properties, including aiding in emotional cleansing, aiding in psychic power, attracting love and money, protecting the wearer from snakebites, eliminating parasitic infections, removing venom, metaphysical associations with the heart energy center, aiding at clearing obstacles, and aiding in meditation. These properties may be in reference to Mg3(Si2O5)(OH)4 magnesium phyllosilicate hydroxide specifically — rather than the type of Antigorite at issue — since the properties listed above are associated with medical lore as well as spiritualism.
Georgius Agricola (1404-1555) founded natural science on observation rather than speculation. His book, De natura fossilium (1546), is described as the first scientic classification of minerals. He was originally a philologist, he worked in the mining region near Joachimsthal, Germany. As a result of that experience, as well as his compilation on what was known about smelting, many thought of him as the "Father of Mineralogy".