Common Opal and Goethite Physical Properties

Common Opal

Goethite

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1 Physical Properties

1.1 Tenacity

Not Available

1.2 Solubility

Not Available

HCl soluble

1.3 Durability

Not Available

1.4 Specific Gravity

1.98-2.504.27-4.29

1 7.18

1.5 Fracture

Conchoidal, Conchoidal, Gemstones of the world (2001)

Uneven, torn surfaces, (e.g. fractured metals)., Uneven, Gemstones (2009), torn surfaces, (e.g. fractured metals).

1.6 Cleavage

Not Available

Perfect {010}

1.7 Mohs Hardness

5.5-6.55-5.5

2 10

1.8 Chemical Composition

SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)

FeO(OH)Arthur Thomas , Gemstones (2009)

Common Opal and Goethite Chemical Formula

While comparing Common Opal and Goethite physical properties, the important data you should know is its chemical composition. Since chemical formula defines the molecular structure of the crystal, most of the physical properties like color, tenacity, solubility are governed by Common Opal and Goethite chemical formula.

Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Chemical formula of Goethite- FeO(OH)Arthur Thomas , Gemstones (2009)

Compare Blue Gemstones

Common Opal Vs Diamond

Common Opal Vs Dumortierite

Common Opal Vs Dravite

Common Opal and Goethite Specific Gravity

Another important criteria for qualitative analysis of gemstones is Common Opal and Goethite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Common Opal and Goethite Optical Properties during the identification of gemstone. Specific gravity of Common Opal is 4.27-4.29 whereas that of Goethite is 4.27-4.29.