SHOW: Rings 51
Title: Ring. General: 18K Gold ring set with Boulder Opal and Diamond. Material: 18K Gold. Gem: Boulder Opal, Diamond. Method: Cast. Finish: Polished. Mechanics: Bezel Set. Designer: W.van Heeckeren. Craftsman: W.van Heeckeren. Price: AUS $ 8000.00.
18K GOLD is a ternary Gold alloy consisting of:
750 parts/1000 Pure Gold.
125 parts/1000 Pure Silver.
125 parts/1000 Pure Copper.
Annealing temperature: 750 degrees Celsius.
Melting Temperature: 950 degrees Celsius.
Wal.
CASTING is a method by which moulten metal is poured into a mold
in order to achieve the desired shape. In the "Lost
Wax" method, an accurate wax model is made. The wax
model is invested (put in a chrystobalite plaster),
after the investment has set, the wax is burned out in
a Kiln. This leaves a negative cavity into which the
moulten metal may be poured.
Wal.
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.
name: OPAL (Quartz group)
colour: White, gray, blue, green, orange
colour of streak: White
mohs hardness: 5.5-6.5
specific gravity: 1.98-2.20
cleavage: None
fracture: Conchoidal, splintery, brittle
crystal system: Amorphous; kidney or grape-shaped aggregates
chemical composition: SiO2.nH2O hydrous silicon dioxide
transparency: Transparent, opaque
refractive index: 1.44-1.46
double refraction: None
dispersion: None
pleochroism: None
absorption spectrum: Fire opal: 7000-6400, 5900-4000
fluorescence: White:white, bluish, brownish, greenish. Black:usually none
Fire:greenish to brown
name: DIAMOND
colour: Colorless, yellow, brown, sometimes green, blue, reddish, black
colour of streak: None possible
mohs hardness: 10
specific gravity: 3.47 - 3.55
cleavage: Perfect
fracture: Conchoidal to splintery.
crystal system: Isometeric ( cubic ); mainly octahedrons, also
rhombic dodecahedrons, cubes, twins, plates.
chemical composition: C, crystalised carbon.
transparency: Transparent.
refractive index: 2.417 - 2.419
double refraction: None, often anomalous.
dispersion: 0.044
pleochroism: None.
absorption spectrum: Colorless to yellow: 4780, 4650, 4510, 4350, 4015,
4230, 4155, 3900 Blue-green: ( 5370 ), 5040, ( 4980 )
fluorescence: Variable; Colorless and yellow: mostly blue. Brown
and green: often green.