Difference Between Light and Heavy Magnesium Carbonate

The key difference between light and heavy magnesium carbonate is that the light magnesium carbonate (hydromagnesite) consists of 4 water molecules whereas the heavy magnesium carbonate (Dypingite ) contains 5 water molecules.

The name magnesium carbonate refers to the chemical compound that has the chemical formula MgCO3. But, when we call light and heavy magnesium carbonate, it refers to magnesium hydroxy carbonates that have different numbers of water molecules associated with them.

CONTENTS

1. Overview and Key Difference
2. What is Light Magnesium Carbonate
3. What is Heavy Magnesium Carbonate
4. Side by Side Comparison – Light vs Heavy Magnesium Carbonate in Tabular Form
5. Summary

What is Light Magnesium Carbonate?

Light magnesium carbonate is hydromagnesite, that has the chemical formula Mg5(CO3)4(OH)2·4H2O. We call it “light” because it has 4 water molecules. In contrast, the “heavy” forms contain 5 water molecules. We can categorize this compound as a carbonate material, and it has a monoclinic crystal system. Furthermore, the molar mass of one unit of this compound is 467.64 g/mol. It is colorless or white, and the streak color is white.

Figure 01: Hydromagnesite

Moreover, it is transparent to translucent. This compound has a very lightweight. It is insoluble in water. We can find this material in weathered products of magnesium-containing minerals; serpentine, brucite, dolomite and marble. We can use this compound as a flame retardant/fire retardant additive for polymers along with huntite. Moreover, it decomposes endothermically; this decomposition forms water, carbon dioxide and magnesium oxide residue. This thermal decomposition occurs as a three stage process.

What is Heavy Magnesium Carbonate?

Heavy magnesium carbonate is Dypingite that has the chemical formula Mg5(CO3)4(OH)2·5H2O. It has 5 water molecules. Thus, we call it “heavy”. It is a carbonate material having monoclinic crystal system. The molar mass of this compound is 485.65 g/mol. It has a white color, and its streak color is white to gray. Moreover, it is semi-trasparent material. This compound is useful as a smoke suppressant, drying agent and filler material. This is also insoluble in water, but it is soluble in dilute acids.

What is the Difference Between Light and Heavy Magnesium Carbonate?

Light magnesium carbonate is hydromagnesite. The chemical formula of light magnesium carbonate is Mg5(CO3)4(OH)2·4H2O. It contains 4 water molecules. Moreover, it has a white streak color. Apart from that, it has a transparent to translucent nature.

Heavy magnesium carbonate is Dypingite. It contains 5 water molecules. The chemical formula of heavy magnesium carbonate is Mg5(CO3)4(OH)2·5H2O. In addition, it has a white to gray streak color. Apart from that, it has a semi-transparent nature. This is the main difference between light and heavy magnesium carbonate.

Summary – Light vs Heavy Magnesium Carbonate

Light and heavy magnesium carbonates are not carbonates but are magnesium hydroxy carbonates. The difference between light and heavy magnesium carbonate is that the light magnesium carbonate consists of 4 water molecules whereas the heavy magnesium carbonate contains 5 water molecules.

Reference:

1. “Hydromagnesite.” Wikipedia, Wikimedia Foundation, 7 July 2018. Available here  
2. “Light Magnesium Carbonate.” Glaze Chemistry. Available here 

Image Courtesy:

1.’Hydromagnesite-182980’By Rob Lavinsky (CC-BY-SA-3.0) via Commons Wikimedia  

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