Some conch pearls show a flame pattern, and that comes from how their aragonite crystals grow just beneath the surface. When those crystals form in thin, nearly parallel layers, light hits them and scatters, creating a soft flicker across the surface. As the pearl turns, the flame appears to shift—a kind of shimmer known as chatoyancy. Flame is the pattern you see; chatoyancy is the movement that brings it to life. The more tightly aligned the platelets are, the sharper and more vivid the flame tends to be.

Flame shows up in different ways. Some pearls have a fine, silky sheen that glides across the surface. Others reveal bold, dramatic patterns that are often compared to tiger stripes and the most highly coveted. There are also pearls with speckled or snowflake-like flame, which can be beautiful, though generally less valuable. Each pattern is unique to the pearl’s structure and can vary even among pearls of the same size and color.

Five natural conch pearls showing different flame patterns. These include fine, silky flame, bold tiger-like structures, and speckled textures—each shaped by variations in crystal alignment beneath the surface.

The pink color in conch pearls is caused by organic pigments that become embedded into the crystal structure as the pearl forms. Similar pigments are also found in the inner conch shell and are closely related to those found in red coral.

Because the color comes from organic material, it can fade over time with extended exposure to direct sunlight. The same fading can be seen in the shell’s interior when it is left in UV light.

Flame and color together give conch pearls their unmistakable visual identity. Both occur naturally, both are difficult to replicate, and both play a key role in evaluating quality.