SHOW: Rings 143


Title:      Ring.
General:    18K Gold ring set with a Natural Pearl.
Material:   18K Gold.
Gem:        Natural Pearl.
Method:     Constructed, Flame Textured edges.
Finish:     Polished.
Mechanics:  Pegged and Glued.
Designer:   W.van Heeckeren.
Craftsman:  W.van Heeckeren.

Price:      AUS $ 5800.00.












18K GOLD.


        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.












FLAME THICKENING.


       Flame Thickening is done by heating the edge of the metal
                        with a very hot flame until the edge at the flame
                        melts.  The cohesion and surface tension of the
                        moulten metal form the edge into a smooth thickened
                        area.

                                                    Wal.













Technical Data for PEARL.


name:                   PEARL
colour:                 Pink, silver, cream, golden, green, blue, black
colour of streak:       White
mohs hardness:          3-4
specific gravity:       2.60-2.78
cleavage:               None
fracture:               Concoidal or scaly
crystal system:         Microcrystalline
chemical composition:   84-92% calcium-carbonate, 4-13% organic substances,
transparency:           Translucent to opaque
refractive index:       1.52-1.66 Black: 1.53-1.69
double refraction:      Weak or none
dispersion:             None
pleochroism:            None
absorption spectrum:    Not usable
fluorescence:           Weak; not usable. Natural black: red-reddish