Crystals from Russia

In the 19th century, the Ural mines produced blocks of malachite so large that entire rooms could be faced with it. In the Winter Palace in Saint Petersburg, now the Hermitage, the Malachite Room, completed in the 1830s, is the most famous example; Saint Isaac's Cathedral had columns clad in it.

Pink Ural rhodonite was just as prized: the tomb of Empress Maria Alexandrovna in the Peter and Paul Cathedral is carved from it. Amazonite from the Ilmen Mountains, in the southern Urals, and jasper complete this imperial palette.

Malachite is soft (3.5 to 4) and sensitive to acids: no perfume or household products near it, and just a dry cloth to clean it. Its concentric green bands are unique to each bead. Rhodonite, harder (5.5 to 6.5), is recognisable by its black veins of manganese oxide.