Ages for Hydrodelhayelite at Apatitovyi Tsirk (Apatite Cirque; Apatite Circus), Rasvumchorr Mine, Rasvumchorr Mt, Khibiny Massif, Murmansk Oblast, Russia

The cyan highlights indicate which age entries were selected as the "best" for assigning the mineral an age of 413.6Ma - 319.6Ma at this locality