A golden yellow gem variety of Beryl.
Originally reported from both "Hoffnungstrahl"-Pegmatite near Rössing station, Arandis, Arandis District, Erongo Region, Namibia and Litchfield Co., Connecticut, USA.
NOTE: "Heliodor" has been reported from several localities in the Tadjikistan, Afghanistan and Pakistan areas - it is highly likely that all such specimens are lower-grade Aquamarine which has been irradiated to turn it golden yellow. No confirmed and verified evidence of Heliodor being found in the field in these areas has yet been made available, so all "Heliodor" specimens from these areas should be treated with great suspicion. (Ref: ExtraLapis issue on Beryl plus personal communication to J.Ralph from several reliable sources) [30]