Crystal 4 Pins SMD footprint
Because the electrical orientation of the crystal crystal does not matter and package has 180° symmetry, it doesn't really matter which way round the crystal is mounted.  

If you place a mark on the PCB, this will generally be assumed to correspond to pin 1 unless the device has an obvious mark on a different pin.  In the case of the crystal, which is marked only by a different contact shape on the bottom, this may not be obvious to the manufacturer.  If the orientation actually mattered, as it does for most components, you would want to include a detailed assembly specification that cleared up any ambiguities.