What gemstones represent.

Every culture that valued gems attached ideas to them: protection, healing, status, devotion. Most of those ideas grew from what a stone looked like and how it behaved. Red stones were tied to blood and life; blue to the sky and the heavens; green to spring and growth; the hardness of diamond to permanence.

Treat these traditions as stories rather than promises. They are a pleasure to give and to wear, and they are a good way to choose between two stones you already love.

In Sanskrit, ruby is ratnaraj, the king of precious stones. Its red has long stood for passion, courage and vitality. In Burmese tradition warriors believed rubies made them invincible; in medieval Europe the stone was thought to bring health, wisdom and success in love.

Ruby is the birthstone for July and the traditional gift for a fortieth anniversary.

Blue sapphire has been associated with truth, sincerity and constancy. Medieval clergy wore it as a symbol of heaven, and rulers kept it close as a stone of wise judgement. Its reputation for fidelity is one reason sapphires remain a favourite engagement stone.

Sapphire is the birthstone for September and the traditional gift for a forty-fifth anniversary. It also comes in pink, yellow, green and colourless.

Emerald green has meant spring, fertility and new beginnings since antiquity. Cleopatra was famously fond of the stone, and the emerald mines of Egypt supplied the ancient world before the discovery of Colombia's deposits in the sixteenth century changed what fine emerald could be.

Emerald is the birthstone for May and the traditional gift for twentieth and thirty-fifth anniversaries.

The name comes from the Greek adamas, meaning unconquerable, a reference to the hardest natural material known. Diamonds were worn as talismans of strength long before they were cut to sparkle. The tradition of the diamond betrothal ring is often traced to 1477, when Archduke Maximilian of Austria gave one to Mary of Burgundy.

Diamond is the birthstone for April and the traditional gift for a sixtieth anniversary.

Amethyst takes its name from the Greek amethystos, not intoxicated. The ancients believed it kept the wearer clear-headed. Garnet, the January birthstone, was carried by travellers as a stone of safe passage. Aquamarine, named for seawater, was the sailor's talisman for calm seas and a safe return.

None of these needs a legend to justify it. They are among the most wearable coloured stones for their price.

The modern list, as published by the jewellery trade in the United States and adopted widely:

January garnet. February amethyst. March aquamarine or bloodstone. April diamond. May emerald. June pearl, alexandrite or moonstone. July ruby. August peridot, spinel or sardonyx. September sapphire. October opal or tourmaline. November topaz or citrine. December turquoise, zircon or tanzanite.

Several months offer more than one stone, so there is usually a choice of colour and budget.