Accessory · Uniaxial (+)
Zircon in thin section
Small euhedral prisms with very high relief and high birefringence (about 0.047–0.055). May produce pleochroic halos in a surrounding mineral such as biotite.
Plane-polarized light
| Color | Colorless |
|---|---|
| Pleochroism (color change on rotation) | None |
| Relief | Very high |
| Cleavage | None |
| Shape | Euhedral |
Cross-polarized light
| Maximum birefringence | about 0.050 |
|---|---|
| Highest interference color | 3rd-order |
| Extinction | Parallel |
| Twinning | None |
Telling it apart
Can be mistaken for xenotime (higher birefringence), monazite (colored, biaxial) or rutile. Apatite has much lower birefringence.
Where you'll find it
Granite, gneiss, detrital in sandstone
Photo examples
Alex Strekeisen · Search Wikimedia Commons
Photos open on the source sites.
Identify an unknown grain Read interference colors Practice mineral ID
Related minerals
Sources
OpticMin, ATHENA, Univ. of Geneva (P. Perroud) · Alex Strekeisen thin-section collection · Distinguishing features of minerals (UT Arlington) · MIT OCW 12.109 amphibole lab · SEPM Strata: carbonate staining · Wikipedia mineral pages (infobox optical data) · Athabasca University rocks and minerals · Smith College petrography: perthite