Volcano Caps

From Looney Pyramid Games Wiki

Volcano caps are a set of five small objects used in the game Volcano. Often, these are small opaque pyramids, but any five suitable objects will do.

Formerly a product sold by Looney Labs, five small gray pyramids to enable the play of Volcano without requiring a sixth stash. Currently discontinued.

Many other things have been used as caps though, including LEGO pieces, Paper Icehouse, or tiny rubber bands. Practically anything can be used, so long as it clearly denotes which volcanoes are capped and sits on a pyramid fairly stably.