BRIEF DESCRIPTION: The cap of A. huijsmanii is 45 - 60 mm wide, subcampanulate at first, then convex, with a distinct broad umbo in some specimens, dry, with a strongly striate margin (25^±% of the radius); the cap is metallic gray, occasionally slightly darker in the disc. The volva is usually absent.

The gills are free, not too close, white with a flesh-cream tone in mass in mature specimens, and rounded at the cap margin. The short gills are truncate at a right angle or at a slight slant.

The stem is 55 - 70 x 7 - 9 mm, white, narrowing slightly and evenly upward, ornamented with fine white fibrils, and exannulate. The flesh is white and hollow. The volva is membranous, white, and often completely lacking an internal limb.

The spores measure (8.5-) 10.1 - 12.8 (-15.0) x (6.5-) 7.0 - 9.8 (-10.9) µm and are inamyloid and broadly ellipsoid to ellipsoid (infrequently subglobose, infrequently elongate, rarely cylindric). Clamps are uncommon at bases of the basidia.