The key difference between alabaster and marble is that alabaster cannot be polished heavily whereas marble can be polished heavily.
Alabaster and marble are two important types of materials that have applications for decorative purposes.
CONTENTS
1. Overview and Key Difference
2. What is Alabaster
3. What is Marble
4. Alabaster vs Marble in Tabular Form
6. Summary – Alabaster vs Marble
What is Alabaster?
Alabaster is a type of translucent gypsum or calcite material that typically appears in white color and is often carved into ornaments. It is a soft mineral rock that can be processed to get plaster powder. The uses of this material are in the field of geology, archeology, and the stone processing industry. According to geologists, this is a type of gypsum, but chemically it is a hydrous sulfate of calcium.
There are two major types of alabaster: fine-grained type of gypsum, which is massive, and fine-grained type of calcite, which occurs as a banded form. However, these two forms have similar properties such as light-colored appearance, translucent nature, and occurrence as soft stones. Primarily, these stones are used in carving different decorative artifacts.
Generally, the ancient type of alabaster can be described as calcite found in Middle Eastern regions such as Egypt and Mesopotamia. But in medieval Europe, it was used as gypsum. In modern times, alabaster is mostly calcite, but it can be either of these two forms. Both these types are easy to work with and are slightly water-soluble.
We can readily distinguish two alabaster forms through the different hardness values given by the 1.5 – 2.0 range for gypsum alabaster and 3.0 for calcite alabaster. Therefore, gypsum alabaster is very soft and can undergo fingernail scratches, whereas calcite alabaster cannot be scratched from fingernails. Further, calcite alabaster can effervesce upon treatment with HCl acid, but gypsum alabaster tends to remain unchanged when treating it with HCl acid.
What is Marble?
Marble is a type of metamorphic rock containing recrystallized carbonate minerals such as calcite and dolomite. Usually, this material does not occur in a layered manner (not foliated), but there can be exceptions in nature. This material has common applications as a sculpting material and building material.
The metamorphism of sedimentary carbonate rocks can cause the formation of marble. These rocks usually have limestone and dolomite. The process of metamorphism forms different recrystallizations of the carbonate mineral grains. Therefore, the marble material that we get at the end of this metamorphism has an interlocking mosaic of carbonate crystals.
The metamorphism of very pure limestone or dolomite protolith causes the formation of pure white marble. However, the presence of mineral impurities such as clay, silt, sand, iron oxide, and chert can cause the formation of characteristic swirls and veins in marble. For example, green coloration comes when there is serpentine that comes from magnesium-rich limestone or dolomite.
What is the Difference Between Alabaster and Marble?
Alabaster and marble are important materials having a pleasing appearance that makes them suitable for decorative purposes. The key difference between alabaster and marble is that alabaster cannot be polished heavily, whereas marble can be polished heavily. This is because of their differences in hardness. Alabaster is comparatively soft, while marble is comparatively hard.
The below infographic presents the differences between alabaster and marble in tabular form for side-by-side comparison.
Summary – Alabaster vs Marble
Alabaster is a type of translucent gypsum or calcite material that typically appears in white color and often is carved into ornaments. Marble is a type of metamorphic rock containing recrystallized carbonate minerals such as calcite and dolomite. The key difference between alabaster and marble is that alabaster cannot be polished heavily whereas marble can be polished heavily.
Reference:
1. “Marble.” Wikipedia. Wikipedia Foundation.
Image Courtesy:
1. “Taj Mahal in March 2004” By Dhirad (CC BY-SA 3.0) via Commons Wikimedia
2. “Alabaster.whole.600pix” (Public Domain) via Commons Wikimedia