Aquamarine is the modern primary birthstone for March, with bloodstone serving as the traditional alternate that the contemporary American birthstone list also recognises. The pairing reflects the broader pattern of the official birthstone calendar — a modern primary stone established in the early twentieth century to support commercial gem sales, with traditional and historical alternates that connect the modern designations to older birthstone traditions stretching back to medieval and antique usage. Both March stones have meaningful trade significance and distinct collector audiences, and the pairing covers a wider range of price points and aesthetic preferences than a single designation would.

Aquamarine

Aquamarine is the blue to blue-green variety of beryl, the same mineral species as emerald and morganite. The colour is produced by iron in the beryl structure, with Fe²⁺ and Fe³⁺ contributing different absorption patterns that combine to produce the characteristic light blue to green-blue body colour. Hardness on the Mohs scale is 7.5 to 8, with refractive indices of 1.577 to 1.583, suitable for jewellery use across all standard applications. The species occurs principally in granitic pegmatites and in associated alluvial deposits, with major sources in Brazil (Minas Gerais), Madagascar, Pakistan, Nigeria, Mozambique, and Russia.

Heat treatment is standard in the trade for aquamarine, used to reduce the green component of the colour and produce a cleaner pure blue. The treatment is stable and accepted in trade, and untreated aquamarines that show natural blue colour without heat treatment command modest premiums for collectors who value untreated material. Inclusions in aquamarine are generally fewer than in emerald, with eye-clean material relatively common in commercial sizes.

Bloodstone

Bloodstone is a dark green chalcedony — a microcrystalline form of quartz — characterised by red iron-oxide spots scattered through the dark green body. The combination of dark green with red flecks gives the stone its characteristic appearance, with the trade name reflecting the visual association of the red spots with drops of blood. Hardness on the Mohs scale is 7, suitable for ring use and other jewellery applications, and the material is opaque to translucent, typically cut as cabochon or carved into intaglios and other decorative forms.

Bloodstone has historical significance as the traditional March birthstone in older birthstone calendars and as a stone of ecclesiastical use in medieval and Renaissance Christianity, where the red spots were associated with the wounds of Christ. The historical association supported extensive bloodstone use in religious objects and devotional jewellery during the Christian era. Sources for fine bloodstone include India (Kathiawar in Gujarat), Australia, the United States, and Brazil, with the Indian material historically considered the standard reference.

The modern birthstone calendar

The modern American birthstone list was standardised by the American National Retail Jewelers Association (predecessor to the modern Jewelers of America) in 1912, with subsequent revisions by the American Gem Society and other trade bodies. The calendar consolidated various older birthstone traditions — biblical, astrological, and folk — into a single standard that supported coordinated commercial promotion of birthstone jewellery. The calendar has since been adopted internationally as the de facto reference, with modest national variations.

For March, the 1912 calendar designated aquamarine and bloodstone as the principal options. Subsequent revisions have generally maintained aquamarine as the modern primary stone, reflecting its commercial availability and consumer preference, with bloodstone continuing as the traditional alternate. The dual designation accommodates buyers who prefer the traditional stone alongside those who prefer the modern aquamarine.

In the trade

For trade buyers, the March birthstone category supports steady year-round sales with concentration around birthdays and the gift-giving season. Aquamarine in commercial sizes (1 to 5 carats) is widely available at accessible prices, with significant premiums for larger sizes and for fine-quality untreated material. Bloodstone is a niche category supplied through specialty cutters, with most production for cabochons and decorative carvings rather than faceted gemstones. Both stones support the broader pattern of birthstone-driven retail jewellery sales that constitutes a meaningful share of mid-market and entry-level jewellery business.

Further reading

• GIA — aquamarine reference
• GIA — bloodstone reference
• American Gem Society — birthstone calendar
• Jewelers of America — birthstone reference