Information about Apophyllite

A group of phyllosilicate minerals, including

• Fluorapophyllit-(Cs)
• Fluorapophyllite-(K)
• Fluorapophyllite-(Na)
• Fluorapophyllit-(NH4)
• Hydroxyapophyllite-(K)

In the past, these were broadly referred to as ‘Fluorapophyllite, Hydroxyapophyllite, and Natroapophyllite’ but the nomenclature rules have changed to include the use of both prefix and suffix.

The most common member is fluorapophyllite-(K); however, most specimens from the group are not lab analysed and are simply referred to as ‘apophyllite‘.

Apophyllite is typically transparent to translucent, and colourless to white. It forms good quality, sharp crystals which are associated with zeolite group minerals like stilbite and heulandite.

Uses and History

No real industrial uses – however, it is prized as a collectors mineral due to extremely well formed, aesthetic crystals.

Apophyllite gains its name from the greek word ‘apophyllizo’, meaning ‘it flakes off’, a reference to how the mineral flakes apart when dehydrated by heat due to moisture loss.

Famous locales

Probably the best known locale for apophyllite worldwide is Jalgaon, India – an extremely prolific area which produces much of the apophyllite sold as mineral specimens on the market today. This area also produces zeolite group minerals, sometimes mixed with apophyllite.

Mineralogy

Hazards and Warnings

Sometimes weakly radioactive due to the presence of potassium.

Mineral collectors should wash their hands after handling specimens, to avoid any exposure to potential toxins.

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis.

When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Translations

Further Reading / External Links

• https://www.mindat.org/min-283.html
• https://en.wikipedia.org/wiki/Apophyllite