Not enough information. Please post a new question describing the suspected mis-strike.
A 1934 Washington Quarter in good condition (G4) is worth: $3.50. If its mint state is MS60, the value rises to: $$45.
All error coins need to be seen for an accurate assessment. Take it to a coin dealer for an idea of value, if any.
a quarter
A 1998 Washington quarter is still worth 25 cents.
It's just a quarter, spend it.
This is a common state quarter. It is worth 25 cents.
It's only a quarter, just spend it.
.50
The 2003 Washington quarter with Helen Keller on the reverse is part of the 50 State Quarters Program. In circulated condition, it is worth its face value of 25 cents. If it is in uncirculated or proof condition, it may be worth slightly more to collectors.
The 1850 quarter is worth approximately $400. The amount will vary depending upon the condition of the coin and the seller of the coin. If by chance the date 1850 is directly below the word "California," and George Washington is on the other side, then what you have is actually a 2005 state quarter, and it's worth 25 cents.
Other than a notable few, it is highly unlikely that a mistruck Australian coin made it into general circulation. What year is the coin? In what way is it mistruck? Check your information and resubmit the question.
It's worth 25 cents.