Gary Smith – Forensic Gemology

Gary Smith is a forensic gemologist whose business is in Montoursville, PA, a little town in central Pennsylvania and a repeat speaker for the DC GIA Alumni Association. Gary’s store, Smith’s Jewelers is has one of the few accredited laboratories in the US. He has a vast knowledge of jewelry history and repair as a result of his training in Asia, Europe and the US.

Lisa Carp and friend enjoy the meeting

Lisa Carp and friend enjoy the meeting

Gary spoke this time about the mechanics of jewelry design, creation, repair and authentication. He began by speaking about die striking, which used until the mid-1950’s. The process of die-striking involves taking the jewelry metal and placing it between steel dies, which are the forms or patterns, then stamping or striking the metal under extreme pressure. The pressure conforms the metal to the shape of the dies. The result is an item of higher density and a tighter atomic structure and a stronger piece. The patterns used in some of the older, more intricate pieces were carved by hand and then struck. These patterns could then be used for multiple pieces. Gary has hundreds of these dies due a fortunate purchase and could reproduce innumerable pieces over his lifetime!

Tools the speaker uses in doing his forensic work

These are some of the tools the speaker uses in doing his forensic work regarding thefts, fire losses, etc.

Casting is a most common way of jewelry manufacturing and is known as the lost wax method and involves many steps. First a mold is made by carving a wax, either by hand or now by cad-cam. The wax is attached to a rubber base. The inside is hollow so that molten metal can be forced into the mold. Then the mold is attached to a base, and a flask is slipped over the base. Once the mold is in the flask, the cast mix or “investment” is put in a vacuum to remove the air bubbles after which it is poured into the flask. Once the investment is dried, the base and flask are removed. The piece is then put into an oven in order to burn out the wax. Next a centrifuge is used to force the melted metal into the investment mold. Duplicate molds can be made in a vulcanizer from which 400-500 pieces can be cast.

Here are some of the tools of the trade and a list of materials to check.

Here are some of the tools of the trade and a list of materials to check.

Gary brought with him some of the tools that he made or acquired over the years. They included saws, files, scrapers, gravers, burnishers and rotary brushes to name a few. By understanding the tools and the marks that they make, one can determine of a piece is old, new, how it was made and the degree of craftmanship used. He examines that back of a piece with more scrutiny than the front.

Gary Smith

And this is Gary Smith, who conducted the forensic explanations for the DCGIA chapter in Oct. 2007.

The evening concluded with the attendees examining the tools and examples of jewelry made by them.

Photos by Doris Voight

This entry was posted in Meeting Archives. Bookmark the permalink.

2 Responses to Gary Smith – Forensic Gemology

  1. please direct me to a school in forensic gemology
    I would like to receive this degree
    Mr. Terry
    terryesthoma@yahoo.com

    In Christ We Trust

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s