What is Australia's largest finds?

I was reading with interest that we have found the largest pink and Red diamonds in the world in our soil.

I was thinking since we are obsessed with everything big like the big banana, the big prawn, the big pineapple, the big Marano why don't we look at the biggestest of everything we have in this great land.

I will start with the largest gold we have found
We are the record holders when it comes to gold. The welcome Stranger our largest nugget 72.04kg but the Holterman is 4 times larger 290kg and holds the record for the largest single mass of gold "still a nugget if you ask me gold is gold". Both From the land down under. We also have the largest existing nugget the hand of faith 27.2kgs...

I know we don't hold the world record but what is our largest stones.

Whats our largest Sapphire?
Whats our Largest Opal?
Whats our largest diamond?
Our largest Topaz?

Anything else I have missed.

diamond 104.73 carats Gungulinya-Bunagina diamond

Isn't either the star of Queensland or the Star of Anakie the world's largest sapphire?

The Centenary Stone

A 13.01 ounce (2020ct) yellow sapphire found in 1979 at Sapphire. It is believed to be the largest gem quality sapphire (for faceting) ever found. It was stolen in 1980 and recovered in 1986 and is believed to have been sold into the USA for a multi million dollar figure.

http://www.australiansapphire.com/famous_sapphires.htm

we have the worlds biggest black opal
11,340.95 carats found at lightning ridge NSW

Seems we do have the largest everything. lol