Info & facts

COLOUR collection

The Van Deijl collection includes a variety of coloured stones sourced only from the most reputable suppliers from across the globe and handpicked by our gemologists. Our designers create the most beautiful pieces, handcrafted by expert goldsmiths on site.

THE VALUE of colour

The intensity of colour increases the value of coloured gemstones, whereas diamonds are generally more valuable for its lack of colour. The Van Deijl collection includes highly valued gemstones like Emeralds, Ruby and Sapphire; as well as a variety of other beautiful stones: Tanzanite, Aquamarine, Tourmaline, Citrine, Topaz, Opal, Amethyst, Onyx and Garnet, to name but a few.

Proudly and uniquely African, a special mention must be made of Tanzanite, a popular gemstone discovered more recently.

  • Discovered in East Africa during 1967, and named after the country of its birth, Tanzania, this gemstone transformed the jewellery world.
  • Tanzanite is a velvety blue variety of the mineral zoisite and its rich purples and blues can often have a depth comparable to the finest sapphire. It is trichroic, displaying different colours when viewed from different directions.
  • Tanzanite measures between 6 and 7 on the Mohs scale. It usually has a poor to fair toughness, vitreous to dull luster and polishes well. Because of its relative softness, when included in a ring design, it is recommended for occasional wear only.

Tanzanite is a relatively soft and brittle stone with a rating of 6.5 on the Mohs scale.

    Tanzanite is a special-care gem. Avoid situations where your tanzanite jewellery might be scratched or knocked. Remove tanzanite jewellery before strenuous activities. Occasion pieces like pendants and earrings are recommended.
    Keep your tanzanite clean by polishing it occasionally with a soft, dry cloth and cleaning it once a month. Clean tanzanite jewellery with warm soapy water, brushing it with a soft brush to remove any residues. Dry carefully with a soft cloth before storing. Avoid heat or steam-cleaning and ultra-sonic cleaning. It can lead to discolouring and fracturing. Nicks and scratches can be removed through polishing by a reputable stonecutter. From time to time Tanzanite jewellery should be cleaned professionally. Avoid contact with acids, as tanzanite is easily damaged by hydrochloric and hydrofluoric acids.
    Avoid scratching by folding each item of tanzanite jewellery (even individual earrings) in a protective cloth or fabric bag.
    Care must be taken when setting tanzanite, as the stone is soft and brittle. The setting should be checked once a year by a reputable jeweller. State clearly that your jewellery piece contains a tanzanite when doing repair work, alterations or resizing.

Though the intensity of colour significantly contributes to the beauty of a coloured gemstone, a few additional facts might be useful when making a final choice:

  • HARDNESS: Is the ability of a gemstone to withstand abrasion.
  • MOHS SCALE: Is the standard of hardness, developed by Friedrich Mohs in 1822. Ten well-known minerals were arranged in order of their scratch hardness to serve as a standard of comparison.
  • TOUGHNESS: Is a gem’s resistance to cracking, chipping and breaking.