AllMineralsRock
Sapphire Vs. Tourmaline
Sapphire is a very popular gemstone composed of silicon dioxide.[1] Tourmaline is also a very popular gemstone and its chemical composition is boron silicate.[2]
Quick Facts on Differences of Sapphire and Tourmaline
For a quick recap of the differences sapphire and tourmaline:- For chemical formulas, sapphire is Al2O3 while tourmaline can be (Ca, Al, B)6O18(OH, Cr, F)4, Fe, Fe, K, Li, Mg, Mn)3(Al, Na)(Al or V)6(BO3)3(Si.
- While both sapphire and tourmaline can be vitreous, in terms of luster, sapphire can be adamantine.
- Sapphire streaks colorless while tourmaline streaks white.
- Sapphire can be commonly blue or green while tourmaline can be commonly red.
- Sapphire's hardness is higher than tourmaline - sapphire is 9 and tourmaline ranges from 7 to 7.5 on the Moh's scale.
- Sapphire's specific gravity is higher than tourmaline - sapphire ranges from 3.99 to 4 and tourmaline ranges from 2.82 to 3.9.
Quick Facts on Similarities of Sapphire and Tourmaline
The similarities of sapphire and tourmaline include:- Sapphire and tourmaline both can be opaque, translucent or transparent.
- In terms of crystallography, sapphire and tourmaline both can be hexagonal or trigonal.
- Sapphire's rarity is similar to tourmaline.
Summary of Sapphire
Sapphire is a precious mineral that belongs to the corundum family. It is a variety of aluminum oxide that is distinguished by its blue color, although it can also be found in other colors such as pink, yellow, green, and purple. Sapphire is one of the hardest minerals in the world, with a hardness of 9 on the Mohs scale, making it an ideal material for use in jewelry and industrial applications.Summary of Tourmaline
Tourmaline is a mineral that belongs to the silicate group and is known for its unique crystal structure and the wide range of colors it comes in. It is a complex mineral that contains boron, aluminum, and other elements. Tourmaline is found in many different parts of the world, including Brazil, Afghanistan, Pakistan, and the United States. The mineral can be identified by its prismatic crystal habit, which means that it has a long, column-like shape with flat faces on either end.Table Comparison of Sapphire vs Tourmaline
| Sapphire (src) | Tourmaline (src) | |
|---|---|---|
| Transparency | transparent, translucent, opaque | transparent, translucent, opaque |
| Chemical Formula | Al2O3 | (Ca,K,Na)(Al,Fe,Li,Mg,Mn)3(Al,Cr,Fe,V)6(BO3)3(Si,Al,B)6O18(OH,F)4 |
| Chemical Composition | silicon dioxide | boron silicate |
| Specific Gravity | 3.99, 4, 4.1 | 2.82, 3.9 |
| Hardness | 9 | 7, 7.5 |
| Streak | colorless | white |
| Crystallography | hexagonal, trigonal | hexagonal, trigonal |
| Refractive Index | 1.757, 1.779 | 1.603, 1.82 |
| Hydrous | No | No |
| Colors | common: green, blue sometimes: pink, amber, yellow less common: gray, black, brown, white, orange, purple, violet, colorless, red, gold, multicolor |
common: red sometimes: blue, black less common: gray, pink, brown, green, white, orange, purple, violet, yellow, colorless, multicolor |
| Fracture | conchoidal | conchoidal, uneven |