This is not particularly Celtic in design - as to the length of the vertical and horizontal arms being equal , this is more the "Greek cross"
concept -( as opposed to the "Latin cross" , also referred to as the"Cross of Jesus" with the longer vertical aspect ). Nice Find .
.925 is your sterling silver designation. For some typical examples of "Celtic" crosses look at some Google images of early Irish and
Scottish church yards /graveyards - you'll see the heavy carved stone crosses dating back a thousand years in some cases .