Tourmaline Gemstone Buying Guide. Tourmaline is available in all colors!. Discover its varieties, cuts, clarity, etimology, properties, birthstone, price, etc..
Tourmaline Gemstones is the name for a group of related mineral species, with a very complex chemical composition. The name is derived of the word “tourmali”, this word in singhalese was used for colored gems, mostly zircons.
Tourmaline gems exist in all colors: Multi colored, Bicolor, Red, Pink, Orange, Yellow, Green, Blue, Purple, Violet, Brown, Neon Blue, Colorless, sometimes Asterism, Change Color and Trapiche. ALL.
Achroite - colorless
Bicolor - two or more colors, colored by Fe and Mn.
The most expensive colors of tourmaline gemstones are Paraiba Tourmaline (vivid green and blue with copper bearing), Rubellite Tourmaline (vivid bright red colored gemstone), Indicolite (blue), Chrome Tourmaline (intense green) and Bicolor. The saturated colors have high demand, in the last years the less saturated colors (soft pink tourmalines) have become popular.
Tourmaline is often cut into rectangular shapes because of its prismatic crystal habit, however Tourmaline's gems offer a HUGE VARIETY OF CUTS: oval, round, emerald, pear, heart, trillion, fancy, cabochon, etc. Cat's eye tourmaline is cut into cabochon, and watermelon tourmaline is often cut into slices.
Tourmalines are strongly pleochroic, this is important for cutters, in order to display the richest attractive color. Tourmalines are available in large sizes, however Paraiba tourmaline are common small sizes, as are Chrome Tourmalines or Rubellite Tourmaline.
Mushroom Tourmaline is a rare variety of tourmaline , and owes its name to the natural crystal growth shape, which is very similar to a mushroom. These mushrooms Tourmalines have two colors, a pink outer zone (Rubellite Tourmaline - Elbaite) and a black area in the center (Schorl Tourmaline).
These gemstones display amazing andbeautiful inclusions, and they are ideal forcollectorsandlovers gemstones.
Paraiba tourmaline, Rubellite tourmaline, Watermelon tourmaline, Red and Pink tourmalineswill show eye-visible inclusions unlike the green and blue tourmalines which will show eye-clean inclusions.
Cat's eye tourmaline is usually translucent to opaque (the chatoyancy is because to thin needle-like inclusions).
Tourmaline and Opal are the birthstones for October.In 1952, the Jewelers of America association included the Tourmaline in the list of birthstones, becoming the second birthstone for October.
* Crystal system: Trigonal. * Habit: Prismatic to acicular crystals (often a triangular prism with long and striated parallel to c axis) * Hardness (Mohs): 7 - 7 ½ * Fracture: Sub-Conchoidal, Irregular. * Transparency: Transparent, translucent, opaque. * Streak: White. * Lustre: Vitreous * Dispersion: 0,017 * Density: 2.85 to 3.35 g/cm3 * Optic nature: Uniaxial negative * Refractive index: 1.622 - 1.644 * Birefringence: 0.014 to 0.040 (usually 0.020). * Pleochroism: Light to Strong (when the ordinary ray having a dark color). * Fluorescence: Mostly inert * Absorption spectrum: Variable- according color and/or tourmaline. * Pyroelectric and piezoelectric: By heating as well as by applying pressure, a tourmaline will become electrically charged (will attract dust particles)
Spinel Gemstone Buying Guide. Color and Price, Cut and Sizes, Clarity and Typical inclusiones, where is found, August Birthstone, Famous Spinels and more information.
Talk about SPINELS is to talk of history, the birth of Gemology, of wars and crowns, but above all, of a great gemstone which is rising from the ashes, like the Phoenix, but on this occasion, it was a long times: TWO CENTURIES.
Lo primero que buscamos en las piedras preciosas es subelleza. Pero la belleza es subjetiva y es muy difícil declasificar.
Una cosa que he aprendido con el tiempo es que cuando se venden piedras preciosas sueltas, los compradores suelen ser coleccionistas de gema o bien van a usar la gema para hacerse una pieza de joyería a medida; unanillo de compromiso,de boda, o algo muy especial. En cuyo caso tienen clarísimoel colorque están buscando.
