Rare Giant Heliodor

Richard Offin writes:

Heliodor (golden sun) is the trade name for yellow beryl. Beryl is one of the most well known minerals because of the several famous different gem varieties in the beryl family- the most well known are emerald, aquamarine, heliodor and morganite.

We have on display (for sale), in our Bangkok office, one of the largest gem quality faceted heliodor gemstones in the world. It weighs in at a hefty 508.45 carats. In a contest, it might well take first prize as the most beautiful heliodor gemstone. It is a deep golden yellow color and is eye clean. The cutting style is a modified radiant cut and is clearly competition grade cutting (by a Russian cutter).

This gemstone is definitely a collector’s stone but could also be worn in a pendant setting by a woman who enjoys attracting attention. At US$ 15,254 for the stone ($30/ct), it is affordable for collectors and “hi-so” ladies.

The beryl species of gem is a hexagonal type crystal based on a molecule made up of beryllium, aluminum, silicon and oxygen atoms. The different beryl varieties are named based on color and the particular transitional trace element (coloring agent) present in trace amounts. Heliodor’s color ranges from pale yellow to deep yellowish orange and its color is due to the presence of the ferric form of iron. However, if iron is present in the ferrous state, beryl is colored bluish green to deep blue and hence called by the trade name aquamarine. The presence of chromium results in a deep green and is trade-named emerald. Manganese results in pink (trade-named morganite); manganese in combination with several other trace elements results in a deep rose-red (trade-named bixbite).

Viewed through a special polar lens instrument (polariscope), the strongly colored specimens of the beryl varieties exhibit two distinct colors. Viewed through this instrument, our heliodor exhibits the colors of brownish yellow and lemon yellow.

Most varieties of beryl occur in light colors so our large heliodor specimen is rare not only for it’s size but also for it’s deep saturated color.