The oldest zircons on earth have been found in the Jack Hills of the Narryer Gneiss Terrane of Western Australia. They date to 4.35 billion years ago. Colorless zircons have long been used as a diamond simulant. The typical range of colors for zircon includes white, yellow, orange, red, brown, black, blue, green, and violet. Sizes up to 10 carats are readily available. Zircon is a natural gemstone and should not be confused with synthetic cubic zirconia. The two materials have different chemical compositions and crystal structures.
- Optical Properties
- Characteristic Physical Properties
- Chemistry & Crystallography
Color due to heat treatment. The diagnostic absorption line at 653nm; and a weaker one at 662nm; both lines being rather diffuse.
Color due to uranium. However, the indication of the o ray is seen in the spectrum by the absence of the two lines at 615nm. and 621nm. in the orange. Note in the unpolarized spectrum above these two lines are just visible but are very faint. Slight variations also occur in the strength of various other lines.
Color due to uranium. As the e ray is polarized, although the stone appears the same, the spectrum changes in that the lines at 615nm. And 621nm. are present and stronger.
Color due to uranium. Dark red zircons like many red stones often have a brownish overtone and do not transmit well in the deep blue-violet area of the spectrum. In some, unlike most zircons, there are no obvious lines to be seen not even the usual diagnostic line at 653nm. On close inspection only a few vague shadows can be detected about 590nm 520 nm. and 500nm. close to where some prominent lines may be seen in most other colors of zircon
Color due to uranium. A line at 653nm. becomes sharper and stronger as an indication of the o-ray together with the weaker lines alongside at 660/662nm. Various other fine lines appear throughout the spectrum but are too weak and narrow to be captured in this image
Color due to uranium. Red zircons generally do not show a strong pattern of absorption lines compared to some other colors of zircon. The o-ray chosen here shows the dominant line at 653nm. at its strongest, but the normally strong line at 589nm. is but a weak smudge. Only vague images of the two lines at 484nm and 460 can be seen in the blue. Some red zircons do not display any lines at all
Color due to uranium and structural changes. A weak fuzzy band from 650nm. to 662nm. and indistinct images of other lines suggests this could be an intermediate type zircon
Color due to uranium. The spectroscope here reveals the diagnostic line at 653nm. which, seen here in the o ray, is strong and about 4nm. wide. This is accompanied by the two faint and narrow lines on the long wave side at 660/662nm.These last two lines are usually only resolved by a small hand spectroscope as a single line at 661nm. Other faint lines are seen in the blue and green
Color due to uranium. The original color of this zircon from Myanmar was a bright greenish yellow. After heat treatment to about 900'C in an attempt to produce a deep violet blue color the aborted experiment produced this almost colorless stone which is not unlike a cape series diamond of low color grade. However, the strong sharp spectrum associated with zircons from this source remained intact as seen here.
Color due to uranium. The typical lines at 653nm. and 660/662nm. are less distinct
Color due to uranium and structure changes. A weak and difficult to see fuzzy band from 650nm. to 662nm. and indistinct images of other lines suggests this could be an intermediate type zircon
Here we see the lines at 653nm. and 661nm. become two lines of equal width and intensity with other lines also appearing. A very faint indication of the two lines at 615nm. and 621nm. can just be seen
Color due to uranium. This light brown Sri-Lankan zircon shows very little apart from the dominant line in the red at 653nm. and the faint 661nm. alongside
Color due to uranium and radiation damage.This large dark orange brown zircon of 11cts. from Sri - Lanka displays most of the absorption lines associated with fully crystalline high type material. However the dark orange brown color absorbs strongly in the violet - blue areas making resolution of the lines there difficult. The diagnostic lines at 653nm. and 661nm. are seen at their strongest when a polarizing filter is used to locate the ordinary ray.
Color due to uranium and radiation damage. Although dichroism in this zircon is unusually strong, changing from a pronounced brown in the o-ray to a dark green in the e-ray, the spectrum changes very little apart from the width of the dominant strong band in the red centered at 655nm. This indicates it is possibly an intermediate type without a fully crystalline structure.
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.
High Zircon, Medium Zircon, Low Zircon Or Metamict, Hyacinth, Jacinth, Jargoon Or Jargon, Beccarite, Melichrysos, Sparklite, Starlite, Stremlite
Countries of Origin
Benin; Papua New Guinea; Angola; Cambodia; Kazakhstan; Paraguay; Portugal; Solomon Islands; Greece; Mongolia; Morocco; Unknown; Mali; Guatemala; Guyana; Iraq; Chile; Nepal; Argentina; Seychelles; Ukraine; Ghana; Zambia; India; Canada; Turkey; Belgium; Namibia; Finland; South Africa; Peru; Venezuela (Bolivarian Republic of); Germany; Yemen; Tanzania, United Republic Of; Eritrea; Viet Nam; Guinea; Somalia; Madagascar; Thailand; United Kingdom of Great Britain and Northern Ireland; Libya; Sweden; Malawi; Saint Helena, Ascension and Tristan da Cunha; Liechtenstein; Poland; Bulgaria; Nigeria; Tunisia; Croatia; Syrian Arab Republic; Sri Lanka; United Arab Emirates; Kenya; Switzerland; French Polynesia; Spain; Djibouti; Cuba; Burkina Faso; Mauritania; Swaziland; Congo (the Democratic Republic of the); Israel; Australia; Tajikistan; Estonia; Myanmar; Cameroon; Malaysia; Iceland; Oman; Bosnia And Herzegovina; Armenia; Gabon; Austria; Mozambique; Korea (the Republic of); Luxembourg; Brazil; Algeria; Cabo Verde; Jersey; Slovenia; Lesotho; Colombia; Ecuador; Hungary; Japan; Belarus; Mauritius; Taiwan (Province of China); Bolivia (Plurinational State of); Lao People's Democratic Republic; New Zealand; Senegal; Honduras; Italy; Antarctica; Ethiopia; Afghanistan; Burundi; Russian Federation; Czechia; United States of America; Egypt; Sierra Leone; Malta; Saudi Arabia; Netherlands; Pakistan; China; Ireland; Slovakia; France; Lithuania; Serbia; Kyrgyzstan; Cote D'Ivoire; Romania; Falkland Islands [Malvinas]; Niger; Philippines; Rwanda; Uzbekistan; Bangladesh; Barbados; Norway; Dominican Republic; Mexico; Uganda; Zimbabwe; Suriname; Greenland; Indonesia
Zircon is a beautiful, natural gemstone with a high refractive index and strong dispersion, a gemological way of saying well-cut zircon is actively brilliant and full of fire! What's more, it is available in a broad color range - yellow, brown, orange, red, violet, green, blue, and colorless. When a vast supply of blue zircon hit the world market in the 1920s, George Kunz became suspicious. Before that, most zircon were brown to green. George suspected treatment. Sure enough, a little investigation revealed that the lovely blue stones were heat treated. Interestingly, when the truth was revealed, the stone's popularity remained steady. Why? Savvy consumers loved the blue of the stone so much, they simply didn't care. Zircon is a wearable stone (7 ½ on the hardness scale) whose clear, compelling colors make it as popular today as it was in the 1920s.
Avoid sharp knocks and harsh wear with all Zircon. Avoid prolonged exposure to UV lighting, such as tanning beds and nail polish curing lights, to avoid temporary alteration of color in blue and colorless varieties.
More About Zircon
Marbode, in the 11th century, wrote that zircon was an excellent amulet for travelers and would ensure safety, rest and a warm welcome at the end of a journey. Some later cultures attributed the stone with lending prudence in practical things (linked thereby to financial success), and providing protection from lightning, What do we believe about zircon? We believe that it is lovely. Slow down. Take your time. Enjoy a look at each of those memorable colors.
Cat's Eye Zircon