Mineral notes:

Natrolites from Morocco

by Tomasz Praszkier

   High Atlas in Morocco is vastly built by Mesozoic sedimentary rocks (mosty Jurassic and Cretaceous age) with numerous small syenite intrusions in central part of the massive. Pegmatites and contact metamorphic rocks connected with those intrusions are the source of many interesting mineral specimens. Usually those mineral-rich zones are very small, and they disappear as quick as the show up. The best known minerals from the area are apatites and titanites, prehnites, magnetites, garnets, pyroxenes and amphiboles. But also zeolites - especially pink/orange chabazites, are known from there.

   In 2022, near to village Tirrhist (Thirrhist), located below the famous Tizi n'Inouazane (Tizi-n-Inouzane) pass, natrolite rich zone was found. Vugs lined by a thin layer of drusy analcime overgrown by natrolite have produced a few hounders of the specimens so far. That includes a few dozens of very aesthetic starburst, sprays and hedgehog style clusters - loose or on analcime layer.

   Natrolite crystals from Thirrist are white or colorles transparent, they are 1 to 5 cm big. Diameter of the clusters usually varies from 2 to 5 cm. Sometimes those clusters are preserved as interconnected groups Analcime is not very attractive - white, heavily corroded crystals, in size of a few mm, form the drusy layer lining the vugs.

   A few nice twinned calcite crystals were also found. They are usually a little bit etched on the surface, but still are nicely shaped and yellowish in color. Some of them are intergrown with natrolite making the specimens quite attractive.

Map of Morocco with the natrolite occurrence marked.

Landscape in Tirrhist area in High Atlas, Morocco. Spirifer photo.

Natrolite with calcite from Tirrhist in High Atlas, Morocco.

Natrolite on analcime from Tirrhist in High Atlas, Morocco. Size 4.2 cm. Collection and photo Albert Russ.

Natrolite on analcime from Tirrhist in High Atlas, Morocco. Size 3.7 cm. Collection and photo Albert Russ.

Calcite with natrolite from Tirrhist in High Atlas, Morocco.

Natrolite with calcite from Tirrhist in High Atlas, Morocco.

Natrolite on analcime from Tirrhist in High Atlas, Morocco.

Natrolite on analcime from Tirrhist in High Atlas, Morocco.

Natrolite cluster from Tirrhist in High Atlas, Morocco.

Natrolite on analcime from Tirrhist in High Atlas, Morocco.

Natrolite cluster from Tirrhist in High Atlas, Morocco.

Natrolite cluster from Tirrhist in High Atlas, Morocco.

The same specimen as above in Jeff Scovil's photo.

Natrolite cluster from Tirrhist in High Atlas, Morocco.

The same specimen as above in Jeff Scovil's photo.

Natrolite cluster from Tirrhist in High Atlas, Morocco.