/esoui/art/compass/compass.dds
64x64
Here's galleries for the folders containing those images (has the other associated images):
/compass
/unitframes
/unitattributevisualizer
As far as how I got them, I used google to find an old (from beta) dump of the DDS files and then batch converted them to PNG files using GIMP.
There's also a
list of textures on the Wiki that is similarly from the beta (that list is actually taken from Wykyyd's framework).
I'm hoping it's not too long before ZO officially release things and we can get an up-to-date version of this, as there are many textures that aren't on that list.