Under this name are understood those techniques that are used to improve a gem, many of these techniques are normally accepted as standard treatments while others are considered to be means to create gems or precious materials from otherwise poor and non-marketable materials, therefore the use of these techniques decreases the value of these gems. Gioielleria AMetis does not use treated stones.

BLEACHING: Use of heat, light and / or chemicals to lighten or remove the original color of the gem. It is generally followed by coloring or impregnation treatments. most commonly used on cultured pearls or on clarified and impregnated Jadeite (B-jade).

COATING: Use of special very thin layers of surface coating through various physical and / or chemical processes such as lacquering, inking, pigmentation, pulverization and others to increase or change the color of the gems or even to add special luminous effects. Used to obtain predominantly blue or green colored diamonds, essential for obtaining the infamous Mystical Topazes

STAINING: Introduction of coloring substances into a gem to give it a new color, to intensify an existing color or even to uniform an existing color. Most frequently used in massive gems that have good microporosity. Most used on Jades and Nephrites, Lapis Lazuli, Turquoises but also on less precious hard stones Onyx, Agate etc.

FILLING: Filling of cracked surfaces or micro-cracks with colorless glass, plastics or other similar substances. These processes can improve durability, appearance and / or weight. Used mainly in Rubies.

FLUX HEALING: During the heating processes, fluxes (or simply heat) can be used to heal fractures or cracks that disfigure the appearance of certain gems: this process dissolves the walls of the fractures and deposits the molten gem material, closing the fracture. This technique is commonly used on Burmese rubies from Mong Hsu.

HEATING: Use of heat to alter color, transparency and / or optical effects. Very frequent technique used on Rubies, Emeralds, Sapphires, Tanzanite, Aquamarine, Demantoids, Topazes and Quartzes

IMPREGNATION: Impregnation of porous gems by means of colorless chemical agents (generally plastics) in order to make them more durable and improve their appearance. Widely used in stabilized Turquoises.

LASERING: Use of lasers and chemicals to reach and alter inclusions. Technique used on diamonds.

OILING: Filling of surface cracks and micro-fractures with colorless oils, resins or waxes or other colorless substances except glass or plastics to improve the appearance of the gems. A typical example is the treatment of emeralds with cedar oil.

IRRADIATION: Use of neutron, gamma, ultraviolet and / or electron radiation to change the color of gems. Radiation is often associated with heating processes. It is the treatment used to create the Blue Topazes.

LATTICE DIFFUSION: Diffusion from the outside to the inside of chemical dyes by means of high temperature heating processes to produce color variations and / or asterism phenomena. technique used mainly in widespread Sapphires

WAXING: Impregnation with colorless waxes, paraffins and / or oils in porous or micro-fractured gemstones to improve their appearance. Widespread technique for Emeralds, Jade and Tourmalines.