WORTH more than £1 million, the largest black opal ever to be brought into the UK is to go on show in Suffolk.About the size of a clenched fist, and 529-carat opal is extremely rare, and was found by Australian miner John Wheeler in 1994.

WORTH more than £1 million, the largest black opal ever to be brought into the UK is to go on show in Suffolk.

About the size of a clenched fist, and 529-carat opal is extremely rare, and was found by Australian miner John Wheeler in 1994.

The opal is part of a collection of the finest quality gems, which were part of a display in Australia to mark the turn of the millennium.

It will now be shown at jewellers, Jonathan Lambert, in the Borehamgate centre, King Street, Sudbury, in an exhibition dedicated to opals.

The exhibition comes about as a result of a friendship based on a shared passion for gems that has grown between Mr Wheeler and Mr Lambert,

Mr Wheeler, who lives in Queensland, Australia, said: “I first became interested in black opals because of the beautiful colours and I started mining for them in 1980.

“In 1994 we dug the largest one ever out of the ground - our plot was filled with black opal.”

The process of mining for the rare stones includes drilling a test hole in a 50 square-metre plot of land and then drilling a metre-wide hole for two miners to go down - who then dig a tunnel and send the sandstone to the surface for sifting.

After the raw rocks have been sieved they are sent to be hand cut, which can take days for each opal.

Mr Wheeler said: “They must not have any grey in them or sandstone, and the colours must change as you move the stone - the better the colours and the clearer they are the more expensive they are.

“Before 1990 black opal was practically impossible to find, and it is still very rare - the first sale was in 1904.”

The exhibition of black opals, which will include jewellery, small and large stones, opals in the rocks before they are cut and video footage of mining will be at Jonathan Lambert from Tuesday next week.

Mr Lambert, owner of the jewellery shop in the town, said: “It is brilliant - it's great as a business and it is great for Sudbury.

“To see a collection like this is not going to happen again - it is a once in a lifetime opportunity. People should come along next week just to have a look.”

The 529-carat opal, along with the rest of the collection will be at Jonathan Lambert until Saturday.

lorraine.price@eadt.co.uk

OPAL FACTFILE

n Black Opals are found between 30 and 70 feet deep in Lighting Ridge in Australia.

n They are called black opals because the underside of the gem is black, but it can also be grey or white.

n It takes between 70 and 100 million years for the opal to form.

n Black Opal is the only opal to be hand cut after it is found in its raw form.

n The colours of the opal can be anything from green and blue to red, which is very rare, but no two stones are the same.

n The first sale of a black opal was in 1904.