A 101.27 carat diamond the size of a squash ball will be sold by auction house Christie's in Hong Kong next month and is likely to fetch up to $7.5 million.The gem is the largest colourless diamond to show on the auction market in 18 years and one of only three colourless diamonds of over 100-carats to have ever been auctioned, Christie's said.

The gem, which is internally faultless but rated VVS1 (very very a little imperfect 1st degree) for simplicity is expected to fetch upwards of $6 million -- a relatively low per-carat price.A 39.34-carat "D" colour, flawless diamond sold for $6.87 million at a Christie's New York sale earlier this month. While rare sophisticated diamonds achieved all-time highs per carat at sales in Geneva late last year, a much-hyped 72.22 carat "D" flawless white diamond failed to sell at a Sotheby's Hong Kong auction earlier this month, suggesting demand for top stones may be waning due to a weakening world economy.

The 101-carat "shield-shape" stone was cut from a 460-carat hunk of rough precious stone and mounted on a tiara, rather than a choker or pendant given its extraordinary thickness.

"With Asia becoming such a vibrant market, it is fitting that this rarest gem should be offered ... to the growing number of collectors in the area," said Francois Curiel, Christie's chairman of jewellery, in a statement.

Naming rights for the gem will be granted to the buyer, who Christie's said might come from Russia or the Middle East.

Other items to feature in Christie's May 28 sale include a coloured diamond ring set with a fancy green diamond estimated to be worth $3 million, as well as a rare emerald and diamond ring set with a 14.31 carat emerald that could fetch $800,000.

The core of the spectacular globular cluster Omega Centauri glitters with the combined light of 2 million stars. The entire cluster contains 10 million stars, and is among the biggest and most massive of some 200 globular clusters orbiting the Milky Way Galaxy. Omega Centauri lies 17,000 light-years from Earth. Astronomers at the Max-Planck Institute for Extraterrestrial Physics in Germany and the University of Texas at Austin have reported on the possible detection of an intermediate-mass black hole in the core of Omega Centauri.

The result is primarily based on spectroscopic measurements obtained with the Gemini South observatory in Chile which suggest the stars are moving around the central core of the cluster at higher than expected velocities. Among the possible explanations for these speedy stars -- and the one favored by their study -- is that an intermediate-mass black hole of approximately 40,000 solar masses resides at the center of Omega Centauri. Its powerful gravitational field speeds up the motions of stars near the core. Hubble images taken with the Advanced Camera for Surveys were used in key areas in support of this study: to help pinpoint the center of the cluster, as well as to measure the amount of starlight at the cluster center. Using the European Southern Observatory's Very Large Telescope in Paranal, Chile, team members Eva Noyola and Karl Gebhardt are planning to obtain follow-up observations to help confirm the existence of an intermediate-mass black hole. The Hubble images were taken in June 2002.

Since a long time, the only Burmese gemstone present on our Chanthaburi market was ruby, with sporadic apparitions of some other material like jade, blue sapphire and peridot.

Since a few weeks a big pocket of Myanmar peridot found its way to Chanthaburi.

Plenty of clean stones in good color over 10 carats and even some pieces over 40 are available. We still don't know how long this supply will last. But for sure we will see competing soon Chinese cut and local Thai cut material in the 3 to 5 carats range.

Some very nice rubellite cabs lots from the same source are also in town. This milky material is of even and very attractive pinkish red color. Some single stones in big size have been seen.

All our Chanthaburi staff wishes happy Thai New Year (Songkran) to all of our faithful readers.

Star clusters can be held together tightly by gravity, as is the case with densely packed crowds of hundreds of thousands of stars, called globular clusters. Or, they can be more loosely bound, irregularly shaped groupings of up to several thousands of stars, like the open clusters shown in this image.

The stars in these open clusters are all relatively young and were born from the same cloud of interstellar gas. Just as old school-friends drift apart after graduation, the stars in an open cluster will only remain together for a limited time and gradually disperse into space, pulled away by the gravitational tugs of other passing clusters and clouds of gas. Most open clusters dissolve within a few hundred million years, whereas the more tightly bound globular clusters can exist for many billions of years.

Open star clusters make excellent astronomical laboratories. The stars may have different masses, but all are at about the same distance, move in the same general direction, and have approximately the same age and chemical composition. They can be studied and compared to find out more about stellar evolution, the ages of such clusters, and much more.

The Small Magellanic Cloud, which hosts the two star clusters, is one of the small satellite galaxies of the Milky Way. It can be seen with the unaided eye as a hazy patch in the constellation Tucana (the Toucan) in the Southern Hemisphere. The Small Magellanic Cloud is rich in gas nebulae and star clusters. It is most likely that this irregular galaxy has been disrupted through repeated interactions with the Milky Way, resulting in the vigorous star-forming activity seen throughout the cloud. NGC 265 and NGC 290 may very well owe their existence to these close encounters with the Milky Way.