Mica cap

The cap is initially 1–2.5 cm in diameter, oval to cylindrical, but expands to become campanulate (bell-shaped), sometimes with an umbo (a central nipple-like protrusion); finally it flattens somewhat, becoming convex.
The color is yellow-brown or tan often with a darker center, then pale yellow or buff from the margin inwards. When young, the cap surface is covered with white or whitish shiny particles. Coprinellus micaceus is hygrophanous, meaning it assumes different colors depending on its state of hydration.[