[11] Yellow, orange, and red zircon is also known as "hyacinth",[12] from the flower hyacinthus, whose name is of Ancient Greek origin.

It also is resistant to heat, so that detrital zircon grains are sometimes preserved in igneous rocks formed from melted sediments.

[13] Its resistance to weathering, together with its relatively high specific gravity (4.68), make it an important component of the heavy mineral fraction of sandstones.

Connected to internal radiation damage, these processes partially disrupt the crystal structure and partly explain the highly variable properties of zircon.

As zircon becomes more and more modified by internal radiation damage, the density decreases, the crystal structure is compromised, and the color changes.

[15] Zircon occurs in many colors, including reddish brown, yellow, green, blue, gray, and colorless.

[16] In geological settings, the development of pink, red, and purple zircon occurs after hundreds of millions of years, if the crystal has sufficient trace elements to produce color centers.

[23] Transparent zircon is a well-known form of semi-precious gemstone, favored for its high specific gravity (between 4.2 and 4.86) and adamantine luster.

[24] Its Mohs hardness is between that of quartz and topaz, at 7.5 on the 10 point scale, though below that of the similar manmade stone cubic zirconia (8-8.5).

If a zircon is cut with this axis perpendicular to its table, birefringence may be reduced to undetectable levels unless viewed with a jeweler's loupe or other magnifying optics.

Due to its hardness, durability and chemical inertness, zircon persists in sedimentary deposits and is a common constituent of most sands.

[citation needed] Zircon forms economic concentrations within heavy mineral sands ore deposits, within certain pegmatites, and within some rare alkaline volcanic rocks, for example the Toongi Trachyte, Dubbo, New South Wales Australia[32] in association with the zirconium-hafnium minerals eudialyte and armstrongite.

Zircons contain trace amounts of uranium and thorium (from 10 ppm up to 1 wt%)[14] and can be dated using several modern analytical techniques.

In addition, the oxygen isotopic compositions of some of these zircons have been interpreted to indicate that more than 4.3 billion years ago there was already liquid water on the surface of the Earth.