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.