Gemstones and Birthstones: Star Sapphires, a Gem with Stars for the Stars

Sapphires are endlessly fascinating and if they’re your birthstone, your collection will never be complete. In addition to coming in every color of the rainbow, sapphires can be little performers. Color change sapphires, of course, but sapphires may also be phenomenal “stars.”

RIGHT: This blue star sapphire is the gold standard. A sharp star in a beautiful transparent blue body. The sharpness of the needles is clearly visible here. Photo by Mia Dixon, courtesy Pala International.

Almost all gemstones contain inclusions of some kind, bits and pieces of their environment collected as they grew under stressful (to say the least) conditions. One type of inclusion that grows in sapphires are very slender long crystals called—of course—needles. These usually grow along the three axes of the crystal, which are oriented nicely at 60 degrees from each other. When a bunch of needles grow in all these directions, and the stone is cut into a well-planned cabochon, boom! In sunlight or a sharp indoor light, a six-legged star will float on the surface of the cab.

This is because the curved dome of the cab combined with the fine internal needles react like light on the curve of a spool of thread—there is a thin focused sheen of light over the highest point of the curve. When you have three directions of “threads” over the curve, you get three sharp lines of light—and a star.

A lot of star sapphires are gray or bluish gray. But this 35.55 cts gray sapphire makes up for it by the gorgeous, bright, sharp star! Photo by Mia Dixon, courtesy Pala International.

A good star should have sharp, well-defined legs of equal length. But inclusions are notoriously bad at following directions. They may be coarse instead of fine, producing a fuzzy star. They may collect densely in one direction, but less densely in others resulting in broken or missing legs.

Most people are familiar with black star sapphires, which can produce a lovely star, but they are usually opaque, and heavily color zoned. Often stars lack color and are white, gray or, at best, bluish gray.

But when the stone comes in one of sapphires saturated colors, the needles are so infinitesimally fine that the sapphire appears almost transparent, and the star is sharp and bright, they are simply, in a word, Wow!

Star sapphires seem to have fallen out of fashion. But in the 1930s and 40s, it seemed, no self-respecting Silver Screen star’s wardrobe would be complete without a star sapphire. Last year I had the chance to review a wonderful book called If these Jewels Could Talk: The Legends Behind Celebrity Gems, by Beth Bernstein. I was surprised to see the number of famous actresses wearing huge star sapphires: 50, 60, 70 carats and more. Mary Pickford had a 182-carat star called the Star of Bombay (now in the Smithsonian Institution.)

Myrna Loy, Mary Pickford, Joan Crawford, Jean Harlow, and Carole Lombard also sported these gemstones, often in their films. Lombard’s sapphire brooch showed up at her shoulder, her bodice, and pinned to her hat. They loved them, wore them, and I was surprised to learn, many of these women bought their own jewelry. They were women of power, influence, and independent means, and they showed it in their jewelry.

For more on sapphires, see these other articles by Sharon:
Gemstones & Birthstones: Smokin’ Sapphires, Just the Facts
Gemstones and Birthstones: Sapphire — Beautiful Blue and All Colors of the Rainbow

If These Jewels Could Talk: The Legends Behind Celebrity Gems is a delightful history of gemstones of the silver screen and the women who loved them.

Sharon Elaine Thompson is a GG and FGA who has been writing on gemstone and jewelry topics for Lapidary Journal Jewelry Artist since 1987. She also writes a line of Birthstone Romances under the name Liz Hartley.

Get more on gemstones in Lapidary Journal Jewelry Artist!