Crystals and water-worn pebbles of topaz are found in abundance in the creeks that flow off the granite of Mount Killiecrankie on Flinders Island, and into Killiecrankie Bay.
The colour of the topaz varies from translucent white to pale yellow, pink and blue, and its high lustre led to it becoming known locally as the Killiecrankie diamond.
Topaz is a hard, glassy, aluminium silicate that derives from pegmatitic cavities in granite.
Usually forming an 'orthorhombic' shape, the crystals are characterised by a perfect basal cleavage and vertically striated prism faces. Topaz crystals of about 20 mm in length are common and some up to 80 mm length have also been reported.
Killiecrankie on Flinders Island was one of the first gem localities discovered in Australia, unearthed in 1810 by New South Wales mineralogist, A.W.H. Humphrey.
Humphrey, along with others, sent the gems back to interested collectors in Europe and America. Topaz was also discovered at about the same time (and possibly even preceding the finding at Killiecrankie) in Kent Bay, Cape Barren Island; these minerals were likewise known as 'Cape Barren diamonds'.
The geologist and gemologist said he had been fossicking for treasures at Lune River more than usual during the coronavirus pandemic. He said although interstate and overseas visitors normally made up 80 per cent of
Mr Ellis and his wife Chrystine Klimek sell and display rocks, fossils, gemstones and Tasmanian jewellery, with school groups sometimes visiting to watch gemstone-cutting demonstrations. The pair have more than 600 products for sale on their website, with the most popular pro .
But Mr Ellis said nothing in his exhaustive collection was as special as his “exquisite” 25cm diameter conifer tree fern trunk fossil. “The fossil wood is quite plentiful down here but what is rare is finding a complete one,” he said. He said tree fern fossils were found by digging through a layer of gravel about 1m underground. His agate and quartz crystal-filled piece was discovered 40 years ago by a collector.
Mr Ellis said he first took an interest in gems and rocks as a teenager when he joined his ¬father fossicking at Lune River – the site of a Jurassic-era forest preserved 280 million years ago.
He said he still does a “bit of a jig or dance” when he finds an exciting piece. “I’ve worked pretty hard at it but it’s not as if I’m working, it’s just fun,” he said. The enthusiast said he has advocated for tree fern fossils to become the state fossil emblem. “Tassie is a hot spot, we’re famous for so much in the mineral world,” he said.
Mon 19 Mar 2018 at 4:36pm
Tasmania's west coast is known for its rugged, rocky coastline and hidden among the landscape are minerals that can make beautiful gemstones.
Quartz, crocoite, topaz and sapphire can be found scattered across the state but jade is less common.
Boris Ellis is very familiar with the west coast and its hidden jewels.
He and his wife Christina have spent years up in the hills looking for flecks of colour in stones they can then turn into jewellery.
A few years ago on one of their regular trips, Mr Ellis stumbled on a gem he never expected to find in Tasmania.
"We'd been to this area before and I just noticed a small fleck," he told Helen Shield on ABC Radio Hobart.
"A small chip of green on the surface amongst some very irregulated shaped brown rocks.
Mr Ellis said the green reminded him of chrysoprase, a bright green and nickel coloured silica quartz gemstone found in parts of Australia.
"When I got the hand lens on to it I knew it wasn't the chrysoprase," he said.
"It had a structure very felted and needle like, interlocking needles, and I knew right away that this was nephrite jade."
Nephrite jade is the more common type of jade, largely found in Pacific rim countries such as New Zealand.
So you can imagine finding this type of jade on the western coast of Tasmania was not expected.
"It was quite a surprise," Mr Ellis said.
"First we had it cut and polished to make sure it was going to come up as a gemstone.
"Then we sent some to a factory in China which specialises in cutting jade; it came back as a wonderful product."
Mr Ellis also sent some to Mineral Resources Tasmania for testing, just to be sure his find was nephrite jade as there are other green stones that resemble jade.
Confirmed, the Ellises were asked to come up with a unique name for the stone.
Mr Ellis finally hit on the name buttongrass, after a Tasmanian native plant common on the west coast.
"It's got greens, yellows, browns, oranges," Mr Ellis said.
"Driving to the west coast at different seasons, those are the colours you see on a buttongrass plain."
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