John Sinkankas, 87; Authority on Gems, Minerals

John Sinkankas, an internationally renowned mineralogist, gemologist, lapidary and author-illustrator whose books on gems and minerals are considered classics in the field, has died. He was 87.

Sinkankas, who had been in declining health due to heart, lung and back problems, died May 17 at Scripps Green Hospital in La Jolla.

“Since George F. Kunz of Tiffany fame at the turn of the last century, he’s probably the most renowned mineralogist, mineral author and gemologist there is,” said Bill Larson, owner of Pala International, a Fallbrook company that mines and sells gems. “People of their magnitude come along once in a hundred years.”

A 25-year Navy aviator, Sinkankas was already well known in the field of mineral sciences when he retired from the military as a captain in 1961.

A self-trained lapidary who started cutting gems in 1947, he began writing a lapidary column for Rocks and Minerals magazine in 1951. Four years later, the first of his 15 books, “Gem Cutting: A Lapidary’s Manual,” was published.

The 1959 publication of his “Gemstones of North America” established Sinkankas’ reputation as a leading authority on gems. He illustrated his books with watercolors of gem crystals, illustrations that are known for their beauty and technical accuracy.

“John was a true Renaissance man because of the way he could do an exquisite watercolor and then write something as scientific and as well researched as ‘Emerald and Other Beryls,’ one of his standards,” said Larson, a longtime friend.

As a gem cutter, Sinkankas excelled in faceting exceptionally large gems. To do so, he designed a faceting machine that was twice the size of a conventional machine.

Three of his large faceted gemstones--a 7,000-carat rock crystal egg, a 4,500-carat smoky quartz egg and a 2,054-carat golden beryl--are on display in the Smithsonian Institution’s Natural History Museum.

Sinkankas was also his field’s best-known bibliophile.

To write his columns on gem cutting, he amassed over 40 years what is considered the leading gemological library in the world: About 10,000 books (the oldest dating to 1511) and 4,000 pamphlets, newspaper and magazine clippings.

A second-generation Lithuanian who spoke Lithuanian and German, he also learned to read Italian, French and Russian so he could read some of the foreign books he bought for his library. And faced with defective bindings, he learned the art of bookbinding.

In 1988, Sinkankas sold his book collection to the Gemological Institute of America in Carlsbad, where it forms the core of the institute’s rare book collection.

As his personal library grew in the early 1970s, Sinkankas and his wife, Marjorie, started Peri Lithon--the Greek translation of “about stones”--a company that specializes in rare and antique earth science books.

Sinkankas’ book collection also led him to write “Gemology: An Annotated Bibliography,” published in 1993.

“It’s the foremost work on gemology,” said Dona Dirlam, director of the Gemological Institute of America’s Richard T. Liddicoat Library and Information Center.

Dirlam said Sinkankas’ engaging personality and voice come through even in the bibliography. “Many bibliographies are quite dry, but his bibliography comes alive because of the stories he tells you about the author or the information that’s in the book and he didn’t hesitate to be critical when that was needed,” she said.

Born in Paterson, N.J., in 1915, Sinkankas developed an interest in minerals in grade school when he began exploring quarries and collecting minerals near his home.

A 1936 graduate of the New Jersey State Teachers College in Paterson, where he met his wife, Sinkankas decided to pursue another early interest after graduation: aviation. He joined the Navy and graduated as a naval aviation cadet from the Naval Air Station in Pensacola, Fla., in 1937.

During World War II, he served as a flight instructor and flew reconnaissance missions in a seaplane patrol squadron.

While stationed in San Diego in the 1950s, he began combining his off-duty writing with mining gems in San Diego County as an amateur.

Sinkankas, who wrote for most mineral and gem publications over the years, continued a monthly column for Rock and Gem magazine until his death.

Among his many awards and honors: In 1984, a new phosphate mineral was named sinkankasite in honor of his contributions to the field.

He is survived by his wife, Marjorie, of Pacific Beach; daughters Sharon Tooley of San Diego and Marjorie Coates of Troutville, Va.; sons John, of Los Angeles, and George, of Knoxville, Tenn.; a brother, William, of Oklahoma City; nine grandchildren; and six great-grandchildren.

A memorial service will be held at 4 p.m. June 29 at the Gemological Institute of America. The family asks that donations in Sinkankas’ memory be made to the Richard T. Liddicoat Gemological Library at the gemological institute, attention Dona Dirlam, 5345 Armada Drive, Carlsbad, CA, 92008