Zeolite (Boiling Stone) Ore

Zeoilte (Boiling Stone) Ore

Zeolite is a term referred to as Boiling Stone. The Term Zeolite is derived from two Greek words Zeo (to boil) and Lite (a stone).  The heated ore supported at the tip of a blowpipe which is used for qualitative research is observed to swell into a pumice-like porous state when air is blown from the mouthpiece. The phrase boiling term comes from this behaviour.

Zeolite is an aluminosilicate mineral (silicate in which silicone atoms are partially replaced with aluminium atoms) containing maily alkali metals such as sodium and potassium and alkaline earth metals such as calcium and magnesium, as well as water molucules (H₂O) in the form of crystals.

(M²⁺,M₂₊)O.Al₂O₃.mSiO₂.nH₂O

M^2+: Mainly Calcium (Ca)

M⁺: Mainly Sodium (Na), Potassium (K)

Zeolite commonly occur in pores of volcanic rocks or inside the rocks in the shape of veins, and are found in the strata near metal ore deposits as well as geothermal power plants and hot springs. Volcanic glass in tuff often transforms into zeolite under the influence of seawater. As a result, besides pure zeolite components, zeolite rock contains minerals such as clay (montmorillonite), iron oxide and feldspar.

Generally, zeolite will generate different zeolite crystal structures, even if it is from the same origin rock, depending on the burial depths, with the pressure on the rock increases to affect the crystal structure with and aid of ground water and hot water. Natural

Among many minerals, the widely distributed natural zeolites are clinoptilolite (often called ‘clino’) and mordenite.

Laumontite is a white plate-like or columnar crystal. Laumontite, which is formed primarily by the action of hot spring water, replaces minerals in rocks or fill cracks making a pattern of veins. Laumontite can be found in aggregates (or gravel) in concrete.

Laumontite is said to react with alkali in cement (alkali-aggregate reaction) to inflate the aggregate which cause cracking.

Applications of zeolite will be in the next article.

Reference: Boiling stone (zeolite), Zeolite Dynamics, Lecture Notes.

Zeolite ore