Hello Ioana and 
A genuine 1889 Queen Victoria crown should be made of 92.5% pure silver, have a diameter of 39mm and weigh 28.3 grams.
If yours is genuine, then it would be worth just the silver melt value in this condition.
Your coin looks to me like a cast base metal counterfeit, probably made to be passed off as a genuine crown in circulation. Whoever received it may have deliberately mutilated it to prevent it from being spent.
You can do a 'silver test' to see if a coin contains silver -
http://goccf.com/t/10649
Here is my genuine 1891 crown for comparison.

A genuine 1889 Queen Victoria crown should be made of 92.5% pure silver, have a diameter of 39mm and weigh 28.3 grams.
If yours is genuine, then it would be worth just the silver melt value in this condition.
Your coin looks to me like a cast base metal counterfeit, probably made to be passed off as a genuine crown in circulation. Whoever received it may have deliberately mutilated it to prevent it from being spent.
You can do a 'silver test' to see if a coin contains silver -
http://goccf.com/t/10649
Here is my genuine 1891 crown for comparison.























