Olive Tourmaline — The Muted Yellow-Green Trade Variety
Olive Tourmaline — The Muted Yellow-Green Trade Variety
A descriptive trade term for tourmaline in the yellowish-green to olive colour range
Olive tourmaline is a descriptive trade term for tourmaline in the yellowish-green to olive-green colour range — the muted earth-tone end of the green tourmaline spectrum, distinct from the vivid greens of fine verdelite and the saturated bluish greens of chrome-coloured material. The term is not a formal varietal designation in the way that verdelite (green tourmaline) and chrome tourmaline are, but is in active commercial use to describe stones whose colour falls in a particular zone of the colour space. Most olive tourmalines are elbaite or dravite by species, with the colour produced by combinations of iron, manganese, and trace chromium acting on the host crystal chemistry.
Colour and species
The olive colour zone in tourmaline encompasses hues ranging from greenish yellow through yellowish green to muted true green, with tone in the medium to medium-dark range and saturation in the moderate range. Pure highly saturated greens fall outside the olive zone — those are described as verdelite or, at the highest saturation with chromium colouring, as chrome tourmaline. Olive tourmalines are typically coloured by iron in the elbaite-schorl compositional range, with manganese contributing yellow components in some material. Dravite — the magnesium-rich tourmaline species — also produces brown-olive material, particularly from East African and Australian deposits.
Sources
Olive tourmaline is recovered from a wide range of localities. Brazilian production from Minas Gerais and the surrounding states yields material across the green-yellow spectrum, including substantial olive-zone stones. East African production, particularly from Tanzania and Kenya, includes both elbaite and dravite material in the olive range. Afghan tourmaline from the Nuristan and Kunar deposits produces some olive material alongside the more famous pink and bicoloured stones. Madagascar, Mozambique, and Namibia each contribute olive material to the international supply. The locality is rarely the headline value driver for olive tourmaline, in contrast to the strong locality premiums attached to fine Paraíba or chrome tourmaline.
Position in the market
Olive tourmaline trades in the moderate price range typical of less saturated coloured stones — generally lower than vivid green or pink tourmaline of equivalent size, and substantially lower than chrome or Paraíba material. The market for olive material is supported by designer jewellery emphasising natural, organic, earth-tone aesthetics, and by buyers who prefer the muted character of the olive zone to the more vivid alternatives. Stones are typically eye-clean to slightly included, with cleaner rough being directed toward the more valuable colour zones and slightly more included material accepted at the olive end of the spectrum.
Cutting and care
Tourmaline of all species has a hardness of 7 to 7.5 on the Mohs scale, fair to good toughness, and pleochroism that requires the cutter to orient the stone carefully — typically with the c-axis perpendicular to the table to maximise depth of colour while avoiding excessive darkening. Olive tourmaline benefits from cuts that maintain enough depth for colour saturation without becoming so deep as to look black face-up; emerald cuts, oval brilliants, and elongated cushion shapes are common cut choices. Care is the standard for tourmaline: ultrasonic and steam cleaning are generally acceptable for clean stones (though some heat-treated material may have stress that ultrasonic can aggravate), and standard mild-soap-and-water cleaning is always appropriate. Heat exposure should be moderate; sudden thermal shock should be avoided.