Watermelon Tourmaline from Afghanistan 28.05 Carats Untreated Cushion

Natural tourmaline from Afghanistan of 28.05 carats, square cushion cut (brilliant crown, step-cut pavilion). The laboratory gives it the trade name watermelon tourmaline — reserved for crystals that combine, within a single stone, a pink zone and a green zone with clearly defined boundaries. Here the colour is described as pink & green in daylight.

Colour zoning is a growth phenomenon: it forms naturally when the chemistry of the melt changes during crystallisation. It cannot be reproduced by treatment, and showing it to advantage depends entirely on the orientation chosen by the lapidary — hence the rarity of cut stones of this weight in which both colours remain readable face-up.

At 28.05 carats for an almost square outline of 16.57 × 16.05 mm, this is a centre stone, destined for a pendant or a ring with character. It comes with its GFCO Gem Lab certificate (Switzerland) including origin determination: Afghanistan.

Characteristics

• Stone: Natural tourmaline, known as watermelon tourmaline (bi-colour)
• Weight: 28.05 carats
• Colour: Pink and green
• Shape: Square cushion, brilliant crown / step-cut pavilion
• Dimensions: 16.57 × 16.05 × 12.74 mm
• Treatment: None
• Refractive index: 1.620 – 1.640
• Density: 3.05
• Origin: Afghanistan
• Certificate: GFCO Gem Lab (no. AAP89885 46540-2)

The stone is delivered with its original certificate. It can be custom-mounted as a ring or pendant by our partner bench jeweller — contact us to discuss.