Loistuvanneet

Loistuvanneet, also known as freckling rays, are a type of small, round structures found in calcite limestone rocks and caves. These features are most commonly seen in caves, but can also appear on rock surfaces outside.

To form loistuvanneet, mineral-rich water flows within the rock, like those present in cave drips, depositing calcite as the water dries. Over time, as the water continues to flow through the area, microscopic particles of calcite attach both to the existing calcite and the larger rock particles. The gradual accumulation of these tiny, loose particles creates a subtly distinct feature from adjacent parts of the rock. This slow, accumulated growth also introduces slight surface engraving to the affected part.

Loistuvanneet are often considered minor, local relief structures and can be seen under a microscope. As precipitation intensifies, they may grow more visible. They are difficult to distinguish at a distance and sometimes appear almost round and flat. Their background is relatively dull and this leads the appearance of standing freckles or small calcium domes submerged on the rock's surface and imperfectly adaptable to colors like different population colors.