Jewelry appraiser Robert Aretz, G.G., remembers when a client came to him with a blue stone pin in an envelope labeled "Aquamarine." Aretz determined the stone in the pin was a 2.5-carat blue diamond. His finding was later confirmed by the GIA Laboratory.

Needless to say, his client was overjoyed. This is just one story of many that Aretz shared to describe his profession as a never-ending, interesting business that's a combination of art and science, when he visited GIA New York last spring to give students an overview of the appraisal business.

He said appraisers have to ask the right questions. When the reason for the appraisal is determined, a correct value can be researched and then applied. He compared buying a piece of jewelry to buying a new car. "Many people are too concerned with resale value when they should focus on locating the best value," he said.

Appraisers must also be ready for their clients' reactions to reports because not all turn out like his pin story. It's not easy, he said, when he has to inform clients that their piece, especially one with personal significance, isn't what they thought it was. He said he's examined stones, sold 60-70 years ago as alexandrite in Mexico or the Far East, that were actually synthetic sapphire or synthetic spinel.

"There is no extra value for sentiment," Aretz said.

Aretz, member of the Appraisers Association of America (AAA) for 23 years and certified member for the last eight, has been in the jewelry business since he was 16 years old. He has 30 years of experience in retail sales, estate jewelry and jewelry manufacturing.

"Training, through classes offered by organizations such as AAA, the International Society of Appraisers (ISA) and the National Association of Jewelry Appraisers (N.A.J.A.), is a must for those interested in becoming an appraiser," he said. He also noted non-G.G. appraisers are becoming a rarity in today's industry.

Students asked about a range of topics, including appraisal pricing guidelines and the objectivity of appraisals. He said location and cost of doing business ultimately determine what appraisers charge.