Lab created cubic zirconia (CZ) is a popular diamond simulant and is well known in the jewelry industry. Natural cubic zirconia was discovered in 1937 as an inclusion in zircon crystals. The first experiments to synthesize cubic zirconia started in the 1960’s and the process was perfected by 1973. CZ is much harder than many other diamond simulants and has high dispersion making it the most popular affordable diamond simulant. CZ has a higher specific gravity, and will show more abrasion, than a diamond. It is often colorless, but it can be “doped” with various elements to produce a wide array of colors.
- Optical Properties
- Characteristic Physical Properties
- Chemistry & Crystallography
LWUV: varies with colorcolorless: greenish yellow or yellow-orangetranslucent pink: strong yellow-greentranslucent white: inert
Cubic Zirconia Colors
Cubic Zirconia Spectra
Color possibly due to rare earths. This rather pale lavender blue CZ did not produce the expected strong rare earth spectrum seen in others of a similar color. On close inspection apart from the moderate absorption from 560nm. to 600nm. other weak lines are seen in the deep blue, green and orange.
Color due to rare earth elements. In the yellow three extremely faint and narrow lines with one in the orange. With weaker lines in the blue
Color due to rare earth elements. Only red & orange light is transmitted down to about 580nm. A group of lines due to neodymium is seen central at 590, along with a single sharp line at 684nm
Color due to rare earth elements. Broad absorption from violet into the green
Color due to neodymium. The main group of complex absorption lines and bands within the orange yellow in the green.
Color due to neodymium. The main group of complex absorption lines and bands within the orange yellow in the green
Color due to erbium The striking sharpness and intensity of the absorption lines in this spectrum is typical of this material when doped with the rare earth erbium. The dominant pair of lines in the green at 518nm and 524nm. are immediately evident, both of which are composed of several closely packed lines. The other lines in the violet, blue and red areas are usually distinct.
Color due to rare earths. Strong sharp absorption lines of various widths which appear progressively stronger to the right, ending in a sharp edge. Located in the red, green, blue and violet areas depict a typical rare earth spectrum
Color due to erbium and neodymium. Often used as a tanzanite simulant this color in CZ is derived by a combination of two rare earth elements. The main absorption lines due to erbium can be seen at 485/490nm; 520/525nm. and a vague group centered at 650nm. The wide group of lines appearing as a diffused band between 570nm. and 605nm. in the yellow area is due to neodymium. Several other lines may be seen in the violet- blue area which may be due to either of these rare earths. Lack of pleochroism and the rare earth spectrum reveals its true nature.
We acknowledge the significant scientific contributions of John S Harris, FGA to the study of gemstone spectra and with deep appreciation to him, acknowledges the use of his images and related notes about gemstones and their spectra in the educational materials on this website.
CZ, Cubic Z, Diamond-Z, Diamonair II, Diamononesque, Diamonite, Djevalite, Phianite, C-Ox, Pearl CZ
Countries of Origin
Tanzania, United Republic Of; Austria; Russian Federation; Unknown; Sri Lanka; China; Namibia; United States of America; Australia; Thailand; Switzerland; India
Normal care for untreated stones. In coated stones color may be affected by polishing, recutting, ultrasonic cleaners, alcohol, and harsh chemicals. Coating can be scratched.