Common Opal and Petalite Physical Properties

Common Opal

Petalite

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1 Physical Properties

1.1 Tenacity

Not Available

Brittle

1.2 Solubility

Not Available

insoluble

1.3 Durability

Not Available

1.4 Specific Gravity

1.98-2.502.40

1 7.18

1.5 Fracture

Conchoidal, Conchoidal, Gemstones of the world (2001)

Subconchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal

1.6 Cleavage

Not Available

Perfect on {001}, poor on {201} with 38.5° angle between the two

1.7 Mohs Hardness

5.5-6.56-6.5

2 10

1.8 Chemical Composition

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

LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references

Common Opal and Petalite Chemical Formula

While comparing Common Opal and Petalite 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 Petalite chemical formula.

Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Chemical formula of Petalite- LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references

Compare Blue Gemstones

Common Opal Vs Dravite

Common Opal Vs Diamond

Common Opal Vs Dumortierite

Common Opal and Petalite Specific Gravity

Another important criteria for qualitative analysis of gemstones is Common Opal and Petalite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Common Opal and Petalite Optical Properties during the identification of gemstone. Specific gravity of Common Opal is 2.40 whereas that of Petalite is 2.40.