Mesolite

Mesolite is a fragile member of the zeolite group, and forms almost exclusively in delicate, needle-like crystal habits. It is closely related to Natrolite and Scolecite, and can appear very similar to them. Chemical analysis or optical tests are sometimes required to distinguish Mesolite from Natrolite and Scolecite, and a single crystal may even contain part of each mineral within different zones of the same crystal.

Mesolite is a very brittle and is easy broken, so care should be exercised when handling specimens. Mesolite is named after the Greek term "Mesos", which means "middle", and "Lithos" - stone. It is named so because Mesolite is intermediary in a series between Natrolite and Scolecite.

Worldwide localities of Mesolite include Talisker Bay, Isle of Skye, Scotland; Haldarsvik, Streymoy island, Faroe Islands (Denmark); and Hvalfjordur, Iceland. Mesolite is less common than other zeolites in the Indian basalts of Maharashtra, but it does occur in nice acicular crystals in Pune (Poona); and a new important find of light yellow balls is noted from Kannad, Aurangabad District.

In the U.S., beautiful sprays of large individual Mesolite crystals have come from the Skookumchuck Dam, Bucoda, Thurston Co., Washington. This locality has produced the largest crystals of this mineral yet. Delicate Mesolite sprays come from Oregon at Bear Creek Quarry, Drain, Douglas Co.; and at Ritter Hot Springs, Grant Co. Small sprays associated with Chabazite are found in the SA Canyon, Gila River, Grant Co., New Mexico. The traprocks of Northern New Jersey are well-known Natrolite producers, but Mesolite is also represented at all the important localities. However, it is often overlooked as Natrolite and labelled as such, due to the difficulty in determining the exact specimen type.