Featuring an attractive display of merchandise, the new West Park street extension of Wiss Sons, Inc., store at 665 Broad street will be opened Monday. The L extension occupies 3,000 square feet. Between two entrances on West Park street a show window of invisible glass will show holiday goods and afford a complete view of the extension interior.

A daylight lighting system, rich appointments and a lounge dividing the new wing from the main store will be features. One of the most interesting departments will be the gemological laboratory, with instruments for testing and identifying all types of gems. It is one of the few in the country. Jerome B. Wiss, company president, is one of the country's 50 certified gemologists.

The merchandise display, the store announces, will be a fine assortment of glass, china, wood, leather and precious metals, representing handiwork of the best craftsmen. The Wiss store was founded in 1848 by Jacob Wiss, grandfather of the firm's present head. Jerome Wiss is president of the Broad Street Association, treasurer of the Newark Chamber of Commerce and active in other civic, educational and philanthropic organizations.