Rare old Aussie coins worth thousands
Check your loose change or that old draw littered with coins to see if any have imperfections from the Royal Australian Mint that could make them worth thousands.
Collectors go crazy for tiny minting errors that are so subtle most go unnoticed to the untrained eye.
A 5c piece from 2007 that incorrectly had the Queen's head on both sides of the coin was sold for thousands.
Town Hall Coins and Collectables expert Matthew Thompson told The Daily Mail this mistake was named a "double-obverse".
"The last one I sold was for $3500," he said.
"That one was in top-end condition and so was worth thousands. One in really poor condition, you'd still be looking at a few hundred for."
Mr Thompson said a simple check through the coins could pocket an eagle-eyed enthusiast thousands.
"I've done it before if I've a bag of coins or change jars. If you just spend a bit of time going through them it can certainly pay off," he said.
Mistakes also include coins being clipped during the minting process or other errors in the stamping of the coin.
"People don't expect institutions like the mint to make mistakes," he said.
"But from time to time things can go awry. If you see mistakes on a coin, if you have something interesting, odd or out of place, then other people are likely to find it interesting, too - that's why people collect."
Mr Thompson said a $1 piece in 2000 was accidentally stamped with the head from a 10c piece.
"It (the head side) is slightly smaller, so it gives a double-ring effect," he said.
"If you see two rings on your dollar coin, it could be worth a few hundred or up to $4000 in really good condition."
About 6000 of these were made but that number is unconfirmed.
A more common mistake is a kangaroo on the $1 coin appearing to have rabbit ears. These coins can be worth about $30.
The Facebook page Detecting Downunder discusses another rare currency that has a slightly curly "2" on the 20 cent piece from 1966. These can fetch up to $2000.
"If you happen to find one of these little beauties, it could be worth big money as these coins are currently selling for between $350 and $800 EACH on eBay, with one at $2000, and they're only getting more valuable each year," the Facebook post said.
The faulty coin has a wavy top edge on the base of the number "2".