TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 OBS

The increase in color darkening of the halo ("pleochroic halo") of alpha-particle radiation damage around a zircon, monazite, xenotine, or apatite crystal is measured as a function of time and alpha-particle activity. However, so many variables (e.g. mica sensitivity to alpha radiation, thermal annealing, color reversal) have been discovered that this dating method has only limited application.  1, record 1, English, - pleochroic%20halo%20dating

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 OBS

La radio-activité provoque dans certains cristaux des troubles de structure (...). Autour des grains de zircon (généralement thorifères) les micas, la cordiérite montrent des "auréoles polychroïques" dont l'aspect et la taille varient avec le temps. Ils y a là une méthode peu précise, mais utilisable.  2, record 1, French, - m%C3%A9thode%20des%20aur%C3%A9oles%20polychro%C3%AFques

Record 1,  Textual support,  Spanish