SHOW: Broach 25
Title: Broach General: This Sterling Silver broach is designed to be worn on the lapel of a coat. It is set with two Amethysts, and is about 5 inches long. Material: Sterling Silver. Gem: Amethyst Method: Hand Forged. The stones are Bezel Set. Finish: Scratchbrushed. Mechanics: The catch is of a standard barrel type. Designer: Walraven van Heeckeren. Craftsman: Walraven van Heeckeren. Price: AUS $ 350.00.
STERLING SILVER is a binary Silver alloy consisting of: 925 parts/1000 Pure Silver and 75 parts/1000 Pure Copper. Annealing temperature: 750 degrees Celsius. Melting Temperature: 950 degrees Celsius. Wal.
FORGING is a method of deforming metal with a hammer on an anvil. In the case of Sterling Silver and the Karat Golds, this must be done COLD! If a hot forging is attempted the precious metals will just crumble. In their PURE form Silver and Gold will allow HOT forging, but there is no benefit to be gained. Wal.
Scratch brushing is a way of finishing Silver by brushing with a very fine brass brush, lubricated with detergent, in order to create a bright but soft look. First the item to be scratch brushed, is finely polished. The item is then annealed and pickled, and then scratch brushed. The entire process is repeated 3 times. Wal.
name: AMETHYST (quartz group) colour: Violet, pale red-violet colour of streak: White mohs hardness: 7 specific gravity: 2.63-2.65 cleavage: None fracture: Conchoidal, very brittle crystal system: Hexagonal (trigonal);hexagonal prisms chemical composition: silicon dioxide transparency: Transparent refractive index: 1.544-1.553 double refraction: +0.009 dispersion: 0.013 pleochroism: Very weak; violet, gray violet absorption spectrum: (5500-5200) fluorescence: Weak; greenish
QUARTZ: Minerals of the same or similar chemcial composition are included under the single group of Quartz (SiO2 resp. SiO2.nH2O) silicon dioxide: Macrocrystalline quartz includes AMETHYST, AVENTURINE, ROCK CRYSTAL, CITRINE, PRASE, HAWK'S EYE, QUARTZ CAT'S EYE, SMOKY QUARTZ, ROSE QUARTZ and TIGER'S EYE. Microcrystalline quartz includes CHALCEDONY GROUP - AGATE, FOSSILISED WOOD, CHROPRASE, HELIOTROPE, JASPER, CORNELIAN, MOSS AGATE, ONYX and SARD. Amorphous quartz includes OPAL GROUP - PRECIOUS OPAL, FIRE OPAL and common opal.
Bezel Setting is done by making a sheet metal surround (the bezel) for the stone. Once the jewelry has been finished the stone is then set. In setting the stone, the stone is placed in the bezel, and the bezel is shrunk in around the stone, by pushing it in little by little evenly around the circumference, until the metal seals tight against the stone. As a finishing touch a flat graver is used to bright cut the edge of the bezel at right angles to the plane of the bezel. Wal.