Although not gold, but silver, I thought you might enjoy this GIA news
release from May 15, 1998…
GIA GTL REPORTS ON SYNTHETIC SAPPHIRE SUNGLASSES FOR SIR
ELTON JOHN
British rock legend Sir Elton John, renowned for his flamboyant passion
for eye-catching spectacles, has had a unique pair of sunglasses created
specially for him - with blue synthetic sapphire lenses. The ultimate
optical fashion statement came into focus at GIA’s Gem Trade Laboratory
(GIA GTL) in New York for a report to identify the material and to
document the item.
“The sunglasses represent one of the more unusual uses for a gem material
we have ever seen,” said Ilene Reinitz, manager of research and
development at GIA GTL, New York. “Because of the way the lenses were
oriented, they functioned well as polarizing sunglasses but I doubt if
they would be comfortable to wear for long. The lenses totaled over 124
carats and the frames were hand made of sterling silver.”
The Winter 1997 issue of Gems & Gemology includes fascinating details
about the growth of the synthetic sapphire and the manufacture of the
frames. The proprietary growth method was carefully controlled to minimize
the stress across the growing crystal, producing large areas of synthetic
corundum that were free from any inclusions and showed no color variations
or growth lines. To choose a specific area optically suitable for lenses,
the manufacturer examined a section of the rough material while it was
immersed in oil to reduce light scattering at the as-grown surface. Next,
two slabs were sawn from adjacent areas of the rough and with the same
optical orientation. A core drill and carborundum slurry were used to cut
circles (lens blanks) from the slabs, and parallel faces were ground on
the blanks. Then the rounds were polished with diamond abrasives and a
final polish was done at an aerospace company to achieve high optical
quality.