How to determine the value of an SMD coil?
You could make an estimate by measuring the package size using calipers and then searching digikey to see what is the most popular value for that package size.  Err on the side of using a value that is too large.

Also, you could follow the traces to see what IC it is connected to, and then look at the reference schematic in the datasheet of that IC and see if it recommends an inductor value.