diamond shaped craft with lights and a slight buzzing sound

The following description is taken from a realitive who saw this craft early one morning on the way to school.  At the time she lived with her mother in the wooded areas in east texas near the La/Tx line...they both saw a diamond shaped craft move very slowly over the van. It had lights on each corner, with a forward light beam emmited from two diffent parts on the front of the craft. It produced a slight buzzing-electric sound that could be heard over the van engine. It moved westerly about 35 mph, with an approximate altitude of 100 feet, and maintained same altitude despite changing topography. The underneath side had strobe-like lights flashing at at regular intervals, lastly dark rectangular bands are seen at diffent lenghts on the bottom side of the craft with a circular light in the middle of the underside
Date may be approximate, although the witness does not indicate that fact.  PD