Be Mesmerized By Tourmaline

You may have come across colourful gemstones called tourmaline in a jewellery shop or jewellery designer. But what are they exactly? Tourmalines exhibit a remarkable array of captivating colours, making them one of the most diverse gem species. Their colour range spans virtually every hue, and various tourmaline varieties have even inspired unique trade names.

1. Rubellite: Refers to pink, red, purplish red, orange-red, or brownish red tourmaline. However, some experts argue that the term should not apply to pink tourmaline.

2. Indicolite: Describes dark violet-blue, blue, or greenish blue tourmaline.

3. Paraíba: Denotes an intense violet-blue, greenish blue, or blue tourmaline originating from the Paraíba state in Brazil.

4. Chrome tourmaline: Despite its name, this variety is predominantly green and owes its color to vanadium, the same element found in Brazilian and African emeralds.

5. Parti-coloured tourmaline: Exhibits more than one color, with common combinations including green and pink.

6. Watermelon tourmaline: Features a pink center surrounded by green. Crystals of this type are often sliced to showcase this unique arrangement.

7. Cat’s-eye tourmaline: Displays a softer, diffused eye effect, typically seen in green, blue, or pink stones. The chatoyancy results from thin, tube-like inclusions formed naturally during the gem’s growth. These stones are cut as cabochons to emphasize the effect.
   

The chemical composition of tourmalines directly influences their physical properties and color. Although they share the same crystal structure, different tourmaline species vary in their chemical makeup. Elbaites, the most common gem-quality tourmalines, contain sodium, lithium, aluminum, and occasionally copper. These gems form in granite-containing pegmatites, rare igneous rocks that can yield crystals up to 1 meter in length. Due to the diverse mineral composition within pegmatites, gem pockets produce tourmalines of varying colors.

Elbaites offer an extensive palette, including green, blue, yellow, pink, red, colorless, and zoned combinations. The colors arise from different trace elements: iron and titanium induce green and blue hues, while manganese contributes to reds and pinks. Some pink and yellow elbaites owe their color to natural or lab-induced radiation.

Elbaites tourmaline before cutting

When choosing tourmaline jewellery, the most important quality is colour. Try to choose those without dark colours, but rather vivid and bright colours. Second, the tourmaline should have high clarity, meaning few inclusions. Third, the tourmaline should have excellent cut, such that the facets are symmetrical. Lastly, a tourmaline that is heavier or has a higher carat weight will cost more.

Similar to other gemstones, if you are purchasing a high value tourmaline jewellery, do request for a gem report to certify its natural origins, and whether it has been treated to improve its appearance.

Beautiful tourmaline pendant