What is the Difference Between Chrysocolla and Turquoise

The key difference between chrysocolla and turquoise is their hardness. The hardness of chrysocolla is 2.5 – 3.5 on the Mohs scale, whereas the hardness of turquoise is 5 – 6 on the same scale.

Chrysocolla and turquoise are minerals having similar appearances and different properties. In terms of their hardness, turquoise is twice as hard as chrysocolla mineral rock.

CONTENTS

1. Overview and Key Difference
2. What is Chrysocolla
3. What is Turquoise
4. Similarities – Chrysocolla and Turquoise
5. Chrysocolla vs Turquoise in Tabular Form
6. Summary –  Chrysocolla vs Turquoise

What is Chrysocolla?

Chrysocolla is a type of phyllosilicate mineral mineraloid that has a unique blue color. It is a hydrated copper phyllosilicate mineral. The chemical formula of this mineral can be given as Cu_2–xAl_x{H_2–xSi₂O₅)(OH)₄•nH₂O (x<1). The crystal system of this substance is orthorhombic, and its appearance can be described as blue, cyan, green, blackish clue to black, or brown; it can be rarely found in yellow color as well.

The crystal habit of this chrysocolla is massive, nodular, and botryoidal. It does not show cleavage, but the fracture is irregular and sub-conchoidal. The tenacity of chrysocolla is brittle to sectile, and its hardness is 2.5 – 3.5 on the Mohs scale. Its luster is described as vitreous to dull, and the mineral streak color is white to blue-green color. It is translucent or opaque. Moreover, the specific gravity of chrysocolla is in the range of 1.9 – 2.4. It is a minor ore of copper, and its secondary origin can be given as the oxidation of zones of copper ore bodies. Some associated minerals of chrysocolla include quartz, limonite, azurite, malachite, cuprite, and others.

What is Turquoise?

Turquoise is a phosphate mineral that is opaque and has a unique blue-green appearance. It is a hydrated phosphate of copper and aluminum. The chemical formula of this mineral can be given as CuAl₆(PO₄)₄(OH)₈·4H₂O. The crystal system of turquoise is triclinic, and the crystal habit is massive and nodular.

The fracture of turquoise can be given as conchoidal, and its hardness is 5 – 6 on the Mohs scale. Its luster is waxy to subvitreous, whereas the mineral streak color is bluish-white. The specific gravity of turquoise is in the range of 2.6 – 2.9. It is fusible when heated, and it is soluble in HCl as well.

This mineral is a rare and valuable type of substance that can be found in finer grades, and it is also categorized as a gemstone. For thousands of years, it has been in use as an ornamental stone. This is because of its unique blue color. The hardness of turquoise is slightly higher than window glass, and it is a cryptocrystalline mineral. It almost never forms single crystals, and all of its properties can be variable. The lower hardness of turquoise comes from its high porosity. According to the X-ray diffraction analysis, the crystal structure of turquoise is triclinic.

The deposits of turquoise may form in different ways, but it always starts with the hydrothermal deposition of copper sulfides. This can occur when hydrothermal fluids tend to leach copper from a host rock. This is typically an intrusion of calc-alkaline rock along with a moderate silica content that can undergo oxidization.

What are the Similarities Between Chrysocolla and Turquoise?

1. Chrysocolla and turquoise are minerals.
2. They are found in arid regions.
3. Both are secondary compounds.

What is the Difference Between Chrysocolla and Turquoise?

Typically, turquoise is hard as twice as chrysocolla. Therefore, the key difference between chrysocolla and turquoise is that the hardness of chrysocolla is 2.5 – 3.5 on the Mohs scale, whereas the hardness of turquoise is 5 – 6 on the same scale.

The below infographic presents the differences between chrysocolla and turquoise in tabular form for side-by-side comparison.

Summary – Chrysocolla vs Turquoise

Chrysocolla is a type of phyllosilicate mineral mineraloid that has a unique blue color appearance. Turquoise is a phosphate mineral that is opaque and has a unique blue-green appearance. The key difference between chrysocolla and turquoise is that the hardness of chrysocolla is 2.5 – 3.5 on the Mohs scale, whereas the hardness of turquoise is 5 – 6 on the same scale.

Reference:

1. “Turquoise Meanings and Uses.” Crystal Vaults, 16 Nov. 2021.

Image Courtesy:

1. “Chrysocolla-230109” By Rob Lavinsky, iRocks.com (CC-BY-SA-3.0) via Commons Wikimedia
2. “Turquoise-40031” By Rob Lavinsky, iRocks.com (CC-BY-SA-3.0) via Commons Wikimedia