Opal and Onyx Physical Properties

Opal

Onyx

Add ⊕

1 Physical Properties

1.1 Tenacity

BrittleWalter Schumann

Not Available

1.2 Solubility

hot salt water

Not Available

1.3 Durability

Not Available

1.4 Specific Gravity

1.98-2.252.55-2.70

1 7.18

1.5 Fracture

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

Not Available

1.6 Cleavage

None

Indiscernible

1.7 Mohs Hardness

5-6.56.5-7

2 10

1.8 Chemical Composition

SiO₂ · nH₂O

SiO₂

Opal and Onyx Chemical Formula

While comparing Opal and Onyx 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 Opal and Onyx chemical formula.

Chemical formula of Opal- SiO₂ · nH₂O
Chemical formula of Onyx- SiO₂

Compare Semi Precious Gemstones

Opal Vs Alexandrite

Opal Vs Amethyst

Opal Vs Lehsunia

Opal and Onyx Specific Gravity

Another important criteria for qualitative analysis of gemstones is Opal and Onyx Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Opal and Onyx Optical Properties during the identification of gemstone. Specific gravity of Opal is 2.55-2.70 whereas that of Onyx is 2.55-2.70.