Watermelon tourmaline is characterized by which specific color zoning?

Watermelon tourmaline is known for its distinctive color zoning, which typically features a pink central zone surrounded by a green outer layer. This unique coloration is the result of the complex structure of the tourmaline mineral group, which allows it to exhibit pleochroism and various colors within the same crystal. The pink center represents the manganese content in the crystal, while the green represents the presence of iron and other elements. This combination creates the striking visual effect that gives watermelon tourmaline its name, resembling the colors found in the fruit itself.

This characteristic of color zoning is one of the key identification features of watermelon tourmaline and is highly sought after in the gemstone market. The clarity and vividness of each color can vary, but the pink and green arrangement is a hallmark of this variety.