AROUND 80 people will soon have a unique piece of Scottish jewellery

worth more than its weight in gold -- thanks to a chance discovery while

a road was being driven from a croft to a peat stack on Lewis almost 10

years ago.

A party of visiting geologists from Edinburgh University, completing a

survey of Britain, were intrigued by the formation of rocks being used

for the foundations.

As they walked along the crofter's track they identified a xenolithic

dike -- a molten mass injected by volcanic action into fissures within

the rock -- which included the rare occurrence of corundum, the mineral

that in its purest state forms sapphire or ruby.

The find was so rare that the area was immediately declared a site of

special scientific interest, although none of the crystals examined

turned out to be of gem quality.

Years went by with the SSI status preventing further digging at the

site, but last year a team from Edinburgh Gemmological Society gained

permission to sift through the rubble. Within 10 minutes Mr Ian Combe,

of Sutherland, regarded as one of Britain's finest gem cutters, was on

the verge of making history . . . and a fortune.

For after examining a ''likely-looking'' football-sized boulder, he

split it to reveal a giant 242-carat sapphire crystal, estimated to be

worth a minimum of #70,000, plus a fragment weighing almost 40 carats.

''We believe this to be the only discovery of gem quality sapphire in

the UK,'' said Fife jeweller Mr Roy Murray, who has clinched a deal with

Mr Combe to make jewellery at Balbirnie Craft Centre, Markinch, from the

80 gemstones the crystal is expected to yield.

The 24 cut stones of one carat or over and another 60 weighing just

under half a carat were likely to be ''the total world production of gem

quality Scottish sapphire,'' said Mr Murray.