- Published: 16 March 2016 16 March 2016
It’s always a treat to visit a large auction, and the catalogue at Bonhams has to be seen to be believed. Oddly some of the items we chose remained unsold but now you can bid online you don’t have to trek far afield, if you’ve never considered ‘attending’ a mineral & gem auction maybe its time!
The images here are from the Bonhams New York lapidary works of art, gemstones and minerals auction from October 2015.
Mentioned in our news article this stunning life-size model of a male skull and the world’s largest known meteorite carving, artist Lee Downey acid-etched the carving to uncover the Gibeon meteorite’s singular, lattice-like “Widmanstätten” pattern.
“Beneath the triangular geometry on the skull’s surface, ‘thumbprints’ of crystallization, graphite spots and ‘light threads’ refracted by the iron nickel layers can be seen for the first time,” Painstaking measurements were taken from an actual skull of a male to ensure
realism and accuracy. Named “Yorick”, the carving draws reference to the dead court jester whose skull triggers Hamlet’s monolog on
mortality in Act 5, Scene I of William Shakespeare’s play.
“Yorick” is also remarkable because it is flawless; polished meteorite typically features pits and cracks. The tridymite on the skull’s forehead – a silica polymorph and an exceptionally rare component in IVA irons – was a part of the Gibeon rock; its location was completely fortuitous.
The cover picture of this issue is courtesey of Bonhams Auctions, a particularly lovely smokey quartz formation named ‘Clouds on a Mountain’ originating from Minas Gerais, Brazil. A large combination specimen. The doubly-terminated smoky quartz is large and
lustrous and displays good transparency. At a single point of attachment a secondary growth crystal of quartz is evident. The combination
presents a poetic landscape reminiscent of a rugged mountain peak and low-lying clouds.
Such an imposing specimen, when properly displayed and illuminated would create a dramatic focal point in any display. Measuring
12 x 11 x 4 ½ in.
- Published: 18 August 2015 18 August 2015
Photo: Richard Lyons courtesy South Australian Museum.
South Australia Museum opal exhibition, including the exhibition’s centerpiece, the Virgin Rainbow, is itself worth in excess of a million dollars and its refracting colours defy description.
We had to put the picture of the renown ‘Virgin Rainbow’ opal on this issue’s cover because it’s simply stunning.
It’s some distance for a lot of our readers but if you happen to have the opportunity to visit the South Australian Museum in Adelaide you’ll sure to be impressed with the superb collection of opals on view.(exibition closes spring 2016)
The Virgin Rainbow was found in 2003 and represents a belemnite fossil 63mm in length weighing 72.65 carats.
Opal formation began when South Australia’s inland sea acted as a breeding ground for plesiosaurs, the marine reptile equivalent of dinosaurs. As plesiosaurs died their bodies sank to the bottom of the sea. Later, after climate change transformed the area into an arid moon landscape, some of these skeletons became opalised fossils.
“In time this sparked the creation of opal mining communities in places like Coober Pedy, Andamooka and Mintabie, which have remained opal mining hubs to this day.
“It is ironic that in the most harsh of terrains the most beautiful of naturally occurring gems are now found.”
Australian opals, are composed of tiny silica spheres of certain sizes, stacked closely together, classified as Opal-A and are usually more stable than opals from other regions such as Ethiopia where the opals are referred to as hydrophane(meaning absorbs water like a sponge, due to an irregular structure which creates gaps).
Famous Australian opals include the Andamooka Opal a cut 203 carat stone presented to Queen Elizabeth II in 1954 & the Light of the World a rough 2268 carat black opal discovered in 1928, subsequently cut into a 252 carat gem.
All photos: courtesy South Australian Museum.