This agaric has a convex to umbonate, fleshy, silvery violet cap.
initially spherical to convex, with the margin rolled inward, then flattened, sometimes with large, broad, central umbo. The margin often cracks star-like, particularly in dry weather. The mushroom is first pale azure violet to pale lilac color, later fading to tan brown or rusty brown. The cap is dry, silkily shiny or tomentose at the margin with membranaceous bronze fragments of the veil. Later the surface becomes cracked into small scales. The gills are sub-crowded, quite thick, broadly adnate, and often slightly emarginate. They are broad, slightly dirty violet when young but usually brown, with only faintly violet tint, later brown, dusted saffron ochre, and with lighter crenulate edge. Stem
tough and thick, bulbously at the base, and spongily stuffed inside. It is vivid violet for a long time in the upper part above the cortina, paler below, and covered with a tough, whitish, boot-like veil, which usually leaves upright zones on the stem. The cortina is violet. The flesh is saffron yellowish-brown to yellowish-brown from the beginning except at the tip of the stem where it is dirty violaceous. It has a strong, bitter taste, particularly when young.
Mycorrhizal, usually with deciduous trees, but also found with conifers, often on acidic soil.
Cortinarius malachius has a slightly scaly cap. Cortinarius camphoratus is similar in appearance and is also violet, but it has pale violet gills which soon turn rusty, and a longer stem with paling flesh at the base. It is associated with conifers, as are Cortinarius alboviolaceus.