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.


        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.


    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.


        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.











Technical Data for AMETHYST.


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




Technical Data for QUARTZ.


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.


        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.