7th Anniversary Stone: Onyx and Lapis Lazuli
7th Anniversary Stone: Onyx and Lapis Lazuli
Two ancient materials marking the threshold of a marriage's second decade
The seventh wedding anniversary is associated with two distinct gemstones depending on tradition: onyx in the United States and lapis lazuli in the United Kingdom. Both materials carry histories stretching back thousands of years, and both possess a visual gravity — deep, saturated, and unapologetically bold — that suits a milestone marking the close of a marriage's first seven years and the beginning of its longer arc.
Onyx: The American Tradition
Onyx is a banded variety of chalcedony, itself a microcrystalline form of quartz (SiO₂). In jewellery contexts, the term almost invariably refers to black onyx — material that is either naturally dark or, far more commonly, dyed to achieve a uniform, intense black. True naturally black onyx exists but is relatively rare; the vast majority of black onyx on the market has been treated with sugar-acid or iron-salt solutions, a practice that is long-established, universally accepted in the trade, and considered permanent. The material has a hardness of 6.5–7 on the Mohs scale, a waxy to vitreous lustre, and takes an excellent polish, making it well suited to cabochons, cameos, intaglios, and flat plaques in both fine and fashion jewellery.
Onyx was prized in ancient Greece and Rome for seal rings and carved cameos, and it featured prominently in Victorian mourning jewellery. In the twentieth century it became a signature material of the Art Deco period, where its stark black provided graphic contrast against diamonds, coral, and platinum. As a seventh-anniversary gift it is understood to symbolise strength, steadfastness, and protection — qualities appropriate to a partnership that has weathered its first years of shared life.
Lapis Lazuli: The British Tradition
Lapis lazuli is not a mineral species but a metamorphic rock, composed principally of lazurite (a feldspathoid mineral responsible for its characteristic intense blue), together with calcite, pyrite, and varying amounts of other minerals including hauyne, sodalite, and wollastonite. The finest material — historically sourced from the Sar-e-Sang deposits in Badakhshan, Afghanistan, a locality that has been mined continuously for more than six thousand years — displays a deep, violetish blue with minimal white calcite veining and an even dusting of gold-coloured pyrite inclusions. Chilean lapis lazuli, from the Andes, tends toward a more greenish blue and is generally considered secondary in quality.
Lapis lazuli has a hardness of approximately 5–6 on the Mohs scale and requires some care in wear. It is porous and sensitive to acids, heat, and prolonged exposure to ultrasonic cleaning. Enhancement by wax or polymer impregnation is common and should be disclosed; dyed material (sometimes sold as dyed jasper or presented as lapis) is also encountered and is considered a separate, lower-value product. Genuine lapis lazuli is distinguished by its characteristic mineral assemblage and, under magnification, by the visible pyrite and calcite inclusions that no dyed substitute replicates convincingly.
Associated in many cultures with wisdom, truth, and celestial knowledge — ground lapis provided the pigment ultramarine used by Renaissance painters for the robes of the Virgin Mary — lapis lazuli carries a symbolic weight that makes it a considered choice for an anniversary stone. In the British tradition, it reflects the deepening of understanding and shared knowledge within a long-term partnership.
Choosing Between the Two
The divergence between American and British lists is not unusual in anniversary gemstone traditions, which were largely codified by jewellery trade associations in the twentieth century and have never been subject to a single international standard. Couples may reasonably draw on either tradition, or combine both — onyx and lapis lazuli are visually complementary and have been paired in jewellery since antiquity. Both materials are widely available, relatively affordable compared with faceted precious stones, and offer considerable scope for custom work in silver, gold, and platinum settings.