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ACRYLIC RESIN : It is a derivative of acrylic acid, it is a thermoplastic substance with outstanding transparency, luster, and great industrial strength. AGATE : A semiprecious hard stone belonging to the chalcedony family, translucent and with concentric layers. AGLET : A small, brooch like ornament sewn to clothing. AIGRETTE : A head ornament worn on a turban, hat, or in the hair to hold bird feathers, made entirely of metal and jewels often shaped in the form of feathers. ALLUVIAL DEPOSITS : Concentration of material that have been separated by weathering from the host rock, and then deposited by rivers or streams. AMAZONITE : A mineral in the feldspar family, with a light green colour. AMBER : A natural material (fossil resin of coniferous plants) with a yellow-re colour. There are excellent imitations of amber; when rubbed, true amber attracts paper. AMINE : A basic organic compound derived from ammonia that is used for manufacturing synthetic resins of various kinds. AMORPHOUS :Without a regular internal atomic structure or external shape. AMULET : An object attributed with magical value worn on a person. ANKLET : A chain or other ornament worn around the ankle. ANKLET WITH ATTACHED TOE RINGS : A composite ornament consisting of toe rings attached by loops to an ankle bracelet. ANNEALING : The heat treating ( softening ) of metal after it has been work-hardened with steel tools, and is necessary between raising and forging stages. ANODIZING : The process for the controlled deposit of oxide on refractory metals. Anodizing is an electrochemical process: a direct current flows from the anode to the cathode through a conducting solution, known as the electrolyte. ARCHIMEDIAN DRILL : Archimedian drill, which is a small device, usually about 10cm long. It is worked by sliding a handle up and down a twisted steel shalt. ARTIST'S JEWELRY : A piece of jewelry made by a painter or sculptor and usually in a limited number of copies. ASSAYING : The process of determining the proportion of precious metal contained in an alloy. Most jewellery is assayed at an official Assay Office and given a hallmark that indicate the type and fineness of the precious metal. ASSOCIATED MINERALS : Minerals found growing together though not necessarily inter grown. ASTERISM : Star effect seen on some stones. AURORA BOREALIS : Faceted glass stones with an iridescent colour. |