Untitled Document
Cubic Zirconia
Cubic Zirconia: Zr02 mixed with Yttrium Oxide (Y203) or Calcium Oxide (CaO)
as a stabilizing agent. Refractive Index:2.16; Relative Density:6; Dispersion:0.060;
Hardness: 8.5. Introduced in 1977, the similarity with the figures for diamond
make this the second best simulant produced to date, second only to a new type
of stone called Moissanite
Cubic Zirconia is an artificial synthetic because the stabilizing oxides used
in its manufacture remain in the finished product and its structure is different
to the natural material Baddeleyite Zr02. This has been such a good imitation
that cubic zirconia can be purchased in both graded colours and clarities. Its
refractive index is near enough for the stone to remain quite brilliant when
tilted, and although the dispersion is higher than that of diamond, is not so
obvious to the layman, and close enough to deceive. The relative density is
much higher than diamond and a loose stone will appear to weigh too much. If
set, it is easy to destructively test the stone with a diamond hardness pen.
| Properties |
| |
Refractive Index (Brilliance) |
Dispersion (Fire) |
Luster
|
Mohs Hardness
|
Toughness
|
Specific Gravity
|
|
Synthetic Moissanite
|
2.65 - 2.69
|
0.104
|
20.4%
|
9.25
|
Excellent
|
3.21
|
|
Diamond
|
2.42
|
0.044
|
17.2%
|
10
|
Good
|
3.52
|
|
Cubic Zirconia
|
2.17
|
0.066
|
N/A
|
8.25
|
Good
|
5.80
|
|
Sapphire
|
1.77
|
0.018
|
7.4%
|
9
|
Excellent
|
4.00
|
|
Emerald
|
1.58
|
0.014
|
4.8%
|
7.5
|
Good to Poor
|
2.72
|
Original document: http://www.jewellerycatalogue.co.uk/diamonds/simulants_info.php
|
