Howlite

This specimen showcases two superb clusters of howlite crystals on massive anhydrite. The crystals are sharp, terminated, and exhibit a chalky grey colouration. These are sourced from the only known location in the world where such crystals occur—at Iona, Nova Scotia. This locality is famous for producing the finest specimens of this unusual borosilicate mineral. The prismatic, well-terminated crystals form a stunning radiating aggregate, beautifully displayed on a matrix of anhydrite.

At the locality in Iona, the howlite crystals are found at the base of a bluff near water level. The unique erosion process at this site contributes to the exposure of the crystals. As waves strike the anhydrite, the mineral absorbs water, gradually transforming into soft, flaky gypsum. This process erodes the outer gypsum layer, continually exposing more anhydrite beneath, which in turn becomes gypsum. Over time, this natural cycle reveals the embedded howlite crystals, which remain intact due to their resistance to water. Many of these howlite clusters eventually fall into the water, where they are further shaped by waves and rocks. The constant interaction between water and mineral is what makes this location so special for collecting rare howlite specimens.

In a recent blog post for the website, David K. Joyce accounts his most recent collecting trip to this locality, read the full article by clicking HERE.