Martin Rees, Jeweller and Pawnbroker

Star Rubies

Rubies which reflect light as a star, 6 pointed stars are the most common, but 12 pointed stars can occur.  The rubies include rutile needles in an organised pattern, and it's the reflection off these needles which form the star.
The star seems to move around as the stone is moved, and is not centred on the light source.  The effect is delightful
They are rather rare these days.  Most rubies are heat-treated to improve clarity, and this dissolves the rutile needles.  This heat treatment is done before the stones are carefully examined, so the workers don't realise they're actually losing these special stones.

Caring for Star Rubies

The stones are hard, and are unlikely to be damaged in normal wear, household dust will not scratch them.  However, like most gems, they are somewhat brittle, and a hard knock can chip them.  They are easily cleaned with any proprietary cleaner or detergent, but do check out our advice on cleaning jewellery.   If the jewellery is valuable, it's wise to obtain professional help.

Precautions when buying

You are unlikely to encounter treated stones, as noted above heat treatment to improve clarity will destroy the star.  However synthetic star rubies were first marketed in 1947.  Be cautious if buying a good quality stone (synthetics are nearly always good quality), and only buy from a reputable source.

We explained good quality star rubies are rare, and this is the only specimen we have.  It has a hint of red in the stone, so it just qualifies as a ruby, however its imperfections are obvious in the picture. At least you can be certain this is a natural untreated ruby!

Star ruby

Above:  A star ruby in a silver mount.  The light source is the reflection to the left, while the star is centred to the right.   Click here for larger image (100 KB)
Below:  Detail of the same stone seen through the microscope.  The intersecting rutile needles are visible.  This picture was taken with the Dino Eye camera.  Click here for larger image (221 KB)

Detail picture of star ruby

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