Diamonds in Australia

[Willy]

Known finds in Australia are;
Lennard river.
Nullargine.
Terowrie.
Herberton.
Stanthorpe.
Copeton.
Bingara.
Narrabri.
Walcha.
Cudgegong.
Macquarie river.
Hill End.
Mt Macdonald and Crookwell.
Mittagong and Berrima.
Delegate.
Chiltern and Beechworth.
Balmoral.
Pieman river.
Smoke creek.
Can anyone add another location for diamond finds?

 

[user 4386]

They vary a lot in productivity (Balmoral was a single diamond, Beechworth are a few hundred carats). Reported at Bathurst in 1851. Copeton-Bingara reasonably important with some production in 1990s. Other localities are Argyle and nearby Smoke Ck alluvials. Bow River. Ellendale (west Kimberleys). Merlin (NT)

 

[saau]

Is this

http://diamond.ozgold.com.au/
a macle

It passes the
-Scratch - cuts glass easily
-Breath - it doesn't fog
-Cold to initial touch
-Casts a strong shadow

Anyone recommend someone to cut into 2 x pear shaped earring 17 carats each ?

 

[user 4386]

Personal experience can be a dangerous thing, but I have never seen a diamond that is so well rounded (see photo of alluvial diamonds). Usually the surface is not so smooth and is irregular, because being the hardest natural substance, there is nothing smoother to grind it down, so shape modification is usually by chipping, and often the octahedral shape is preserved to at least some degree.

Nothing obvious to show it is a macle (twin). Hardness is the best test - many things cut glass easily. A bit of corundum is usually easily come by and if that does not scratch it (but it scratches the corundum) you would know it is diamond.

Looks like major flaws present, but I am not an expert on that.

 

[user 4386]

However well rounded diamonds can occur - in that case it is diamonds that were resorbed in the magma in which they occur before being shed into streams. So hardness is the most conclusive test.

Another diagnostic test is specific gravity Diamonds have a specific gravity of 3,1 to 3,5, corundum 4.0 - unfortunately topaz is 3.5. In comparison, quartz has a specific gravity of 2,6 to 2,7. Topaz will be scratched by corundum.

 

[Willy]

During a trip to Anakie and Rubyvale in the 1960,s I found some nice yellow saphires and heaps of green saphires. No rubies or diamonds but the visit was only 3 days. The Barrington tops looks nice and apparently has a good variety of gems.Guess the weather now is about right or I wait until September. Any tips regarding Barrington Ranges.?

 

[Pat Hogen]

Barrington stones that I have found are small, but down below, on the hillsides are some excellent animal fossils on the road to Nowendoc.

 

[Willy]

Barrington stones that I have found are small, but down below, on the hillsides are some excellent animal fossils on the road to Nowendoc.

When I lived near Wollongong the coal miners would find fossils from the Devonian stratas deep down into the mine shafts. I thought they were valuable but apparently the miners saw so many they lost interest in them over time. Lots of ferns and sea critters.For a young guy still at high school it opened up a world of science that even now I find very interesting. I think the ocean covered a vast area of the eastern seaboard in ancient times.Thanks for the tip about those fossil locations.

 

[MBsearch]

However well rounded diamonds can occur - in that case it is diamonds that were resorbed in the magma in which they occur before being shed into streams. So hardness is the most conclusive test.

Another diagnostic test is specific gravity Diamonds have a specific gravity of 3,1 to 3,5, corundum 4.0 - unfortunately topaz is 3.5. In comparison, quartz has a specific gravity of 2,6 to 2,7. Topaz will be scratched by corundum.

Small brilliant resorbed Copeton stone

 

[MBsearch]

Small brilliant resorbed Copeton stone