Vertex Minerals (ASX:VTX) started commissioning the laser ore sorter/pre-concentrator at the Hill End gravity gold plant in New South Wales, according to a Monday filing with the Australian bourse.

The commissioning of the sorter, which separates gold-bearing quartz ore from waste before it enters the processing plant, is being conducted while the gravity concentrator is processing gold ore, the filing said.

Shares fell past 6% in afternoon trade Monday.