Based on natural zircon specimens of different crystallization degree
the experiments were carried out in respect of possibilities and const
raints of recent techniques of separation of those specimen fragments
which are least altered by secondary processes as only samples suitabl
e for a mostly concordant age values. The considered techniques are as
following: aeral grinding treatment; separation of heaviest mineral f
raction; differential dissolution in hydrogen fluiride acid. Least dis
cordant zircon specimens from crystalline samples and semicrystalline
grains with sufficient fraction of the crystalline phase were separate
d by use of differential dissolution. The comparison with other indepe
ndent treatment techniques proves the absence of predominant uranium a
nd lead removal is such procedure. This techniques could not be applie
d to completely metamict zircons subjected to leaching of lead.