We lost the 1 and 2 cent coins back in the early 90's. Since then the denominations have been as follows.
5 Cent - Smallest and silver in colour
10 Cent - A little larger and still silver coloured
20 Cent - Twice as large and silver coloured
50 Cent - Heavy Coin, 12 sides and silver coloured
1 Dollar - size of the 20 Cent but gold coloured
2 Dollar - size of the 10 Cent but thicker and gold coloured.
All of our Notes are Polymer and come in $5, $10, $10, $50, $100 Denominations. Paper notes were phased out here by the late 80's.
Now we're used to the coins for the $1 and $2 we perfer them. We struggled badly with the small denominations in the US, particularily when all the notes are all the same colour. Our Polymer notes are a different colour for each denomination and machine washable, which gives a new meaning to Money Laundering.
When paying cash for anything here, the price always includes GST and the cost is always rounded up or down to the nearest 5 cents. It was a shock in the US having to deal with lots of 1cent coins as change.
I've attached a link to show what our currency looks like.
http://en.wikipedia.org/wiki/Banknotes_of_the_Australian_dollar Have a look at the current series for Polymer as the paper notes havent existed since 1991
http://en.wikipedia.org/wiki/Coins_of_the_Australian_dollar