The key difference between perlite and zeolite is that perlite appears in white colour whereas zeolite appears in yellow, blue, or green colors.
Perlite is an inorganic compound having a relatively high water content, and it is a type of amorphous volcanic glass. Zeolite, on the other hand, is a microporous aluminosilicate mineral.
CONTENTS
1. Overview and Key Difference
2. What is Perlite
3. What is Zeolite
4. Perlite vs Zeolite in Tabular Form
5. Summary – Perlite vs Zeolite
What is Perlite?
Perlite is an inorganic compound having a relatively high water content and is a type of amorphous volcanic glass. This mineral typically forms through the hydration of obsidian and naturally occurs in the environment. It has the unusual property of greatly expanding upon heating to a sufficient temperature.
Usually, perlite mineral tends to soften itself upon heating to a temperature of about 850 to 900 Celsius degrees. There, the water molecules that are trapped in its structure tend to vaporize and escape from the mineral, causing the material to expand itself to about 7 to 16 times than its original volume. This expanded material appears in brilliant white color. This is because of the reflectivity of the trapped bubbles. When considering the density of perlite, the unexpanded form has a bulk density of about 1100 kg/m3 and the expanded form has a density of about 30 – 150 kg/m3.
Figure 01: Expanded Perlite Mineral
We can observe that perlite is a non-renewable source on Earth. There are only about 700 million tonnes of perlite on Earth as per estimations. The most common reserves are in Armenia, Greece, Turkey, the USA, and Hungary.
There are many different applications and uses of perlite, which include construction and manufacturing of lightweight plasters, concrete, mortar, insulation and ceiling tiles, building composite materials, creating syntactic foam, etc.
What is Zeolite?
Zeolite is a microporous aluminosilicate mineral. It is mainly useful as a catalyst. On a commercial scale, it is useful as an adsorbent. This term came into fame in 1756 after the research of Swedish mineralogist Axel Fredrik Cronstedt. He observed the production of large amounts of steam from water (which occurs inside the material through adsorption) upon rapid heating of a particular material containing stilbite. Depending on this observation, this scientist named this material zeolite, which has the Greek meaning, “zeo” =”to boil”, and “lithos”=”stone”.
Figure 02: Microporous Structure of Zeolite
There is a porous structure in zeolite, which can be associated with a wide variety of cations, including Na+, K+, Ca2+ and Mg2+. These are positively charged ions that can be loosely held. Therefore, these ions can be readily exchanged for other ions upon contact with a solution. The mineral members in the zeolite group include analcime, chabazite, clinoptilolite, stilbite, etc.
When considering the properties of zeolite, the naturally occurring forms can react with alkaline groundwater. Moreover, these materials can get crystallized in post-depositional environments over a large period of time. Furthermore, the natural zeolite forms rarely occur in the pure state. They are usually contaminated with other minerals, metals, quartz, etc.
What is the Difference Between Perlite and Zeolite?
Perlite and zeolite are mineral substances that occur naturally. Perlite is an inorganic compound having a relatively high water content, and it is an amorphous volcanic glass type. Zeolite is a microporous aluminosilicate mineral. The key difference between perlite and zeolite is that perlite appears in white color whereas zeolite appears in yellow, blue, or green colors. Moreover, while perlite has an amorphous glass structure, zeolite has a microporous structure.
The following infographic lists the differences between perlite and zeolite in tabular form for side by side comparison.
Summary – Perlite vs Zeolite
Perlite and zeolite are mineral substances that occur naturally. The key difference between perlite and zeolite is that perlite appears in white color whereas zeolite appears in yellow, blue, or green colors.
Reference:
1. Menezes, Raquel Aranha de, et al. “Color and Shade Parameters of Ultramarine Zeolitic Pigments Synthesized from Kaolin Waste.” Materials Research, ABM, ABC, ABPol, 1 Aug. 2014.
Image Courtesy:
1. “PerliteUSGOV” (Public Domain) via Commons Wikimedia
2. “Zeolite structure as an assembly of tetrahedra” By François-Xavier Coudert – Own work (CC BY 4.0) via Commons Wikimedia
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