The 65th wedding anniversary is among the rarest of marital milestones, and the gemstone most widely associated with it in the United States is the star sapphire — a corundum variety that displays asterism, the optical phenomenon in which reflected light forms a luminous six-rayed star across the surface of a cabochon-cut stone. The pairing is apt: just as a 65-year marriage represents something extraordinary and enduring, the star sapphire is itself an uncommon gem whose defining characteristic — a star that seems to float and shift with every movement — sets it apart from even the finest faceted sapphires.

Turn this star sapphire into a custom engagement ring: made in Toronto, Canada.

Anniversary List Standardisation

Anniversary gemstone lists are not governed by any single international authority, and the lists in common use today derive from a mixture of American retail tradition, jewellery industry guidance, and periodic revisions by organisations such as the American National Retail Jewelers Association. The earlier milestones — diamond at 60 years, gold at 50 — are near-universally agreed upon, but designations beyond the 60th anniversary are less consistently standardised across different published lists. Star sapphire at 65 years is nonetheless widely recognised in North American trade and gift-giving contexts, and the designation appears in numerous reputable jewellery and gift guides. Couples seeking a gemstone to mark this milestone will find star sapphire the most broadly accepted choice.

The Phenomenon of Asterism

Star sapphires owe their distinctive appearance to microscopic needle-like inclusions of rutile (titanium dioxide) oriented in three intersecting directions within the hexagonal crystal structure of corundum. When the stone is cut en cabochon — with a smooth, domed top and a flat or slightly curved base — and oriented with the dome perpendicular to the crystal's c-axis, incident light reflects off the rutile needles to produce a sharp, six-rayed star. In the finest specimens, the star is centred, well-defined, and moves fluidly across the surface as the viewing angle changes. Twelve-rayed stars occur occasionally, produced by two intersecting sets of inclusions, though they are considerably rarer.

The body colour of star sapphires ranges widely. Blue is the most traditional and commercially significant colour, with the most prized stones displaying a medium to medium-dark violetish-blue or pure blue body colour. Grey and black star sapphires are common and more modestly priced; pink and purple star sapphires are less frequently encountered and can command significant premiums when the colour is vivid and the star is strong. The simultaneous presence of a fine body colour and a sharp, well-centred star in a single stone is relatively uncommon, which is precisely what makes exceptional specimens so desirable.

Notable Sources

The most historically celebrated star sapphires have come from Sri Lanka (formerly Ceylon), which has produced some of the largest and most famous examples known, including the Star of India (563 carats, housed at the American Museum of Natural History, New York) and the Star of Asia (330 carats, at the Smithsonian Institution). Myanmar (Burma) and Thailand are also significant sources. More recently, deposits in Australia — particularly in Queensland and New South Wales — have yielded large quantities of blue-grey and black star sapphires, while stones from Cambodia and Madagascar also appear in the trade.

Book a private viewing in Toronto, Canada and hold our sapphires in your hand.

Treatments and Disclosure

Star sapphires are subject to some of the same treatments applied to faceted corundum, though the situation is somewhat different in practice. Heat treatment, which is standard and broadly accepted for faceted sapphires, can dissolve the rutile needles responsible for asterism and thereby destroy the star effect; for this reason, many fine star sapphires are sold untreated. Conversely, a process sometimes called lattice diffusion of titanium into low-quality corundum can artificially induce or enhance asterism in stones that would not otherwise display it. Such treated stones should be disclosed as such, and reputable laboratories — including the Gemmological Institute of America (GIA) and Gübelin Gem Lab — can identify diffusion treatment. When purchasing a star sapphire of significant value, a laboratory report from a recognised gemmological laboratory is advisable.

Selecting a Star Sapphire for a 65th Anniversary

The qualities to prioritise when selecting a star sapphire as an anniversary gift are, in approximate order of importance: the sharpness and centredness of the star, the body colour (blue being most traditional), the transparency or translucency of the stone, and the overall symmetry of the cabochon. A star that is crisp and well-centred under a single light source, combined with a pleasing blue body colour, represents the classic ideal. Stones are available across a wide range of sizes; unlike faceted sapphires, star sapphires are frequently encountered in larger calibrations because the cabochon cut retains more rough weight. Settings that allow light to enter from below — open-backed or bezel settings with a thin base — will best display the asterism.

Explore our star sapphire collection — hand-selected and GIA-certified, in Toronto, Canada.