AllMineralsRock
Tourmaline Vs. Turquoise
Tourmaline is a very popular gemstone composed of boron silicate.[1] Turquoise is also a very popular gemstone and its chemical composition is copper aluminum phosphate.[2]
Quick Facts on Differences of Tourmaline and Turquoise
For a quick recap of the differences tourmaline and turquoise:- While both tourmaline and turquoise can be opaque or translucent, tourmaline can be transparent.
- In terms of crystallography, tourmaline can be hexagonal or trigonal while turquoise is triclinic.
- For chemical formulas, 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 turquoise is CuAl6(PO4)4(OH)8• 4H2O.
- While both tourmaline and turquoise is vitreous, in terms of luster, turquoise can be dull or waxy.
- Tourmaline can be commonly red while turquoise can be commonly blue or green.
- Tourmaline's hardness is higher than turquoise - tourmaline ranges from 7 to 7.5 and turquoise ranges from 5 to 6 on the Moh's scale.
- Tourmaline's specific gravity is higher than turquoise - tourmaline ranges from 2.82 to 3.9 and turquoise ranges from 2.4 to 2.6.
Quick Facts on Similarities of Tourmaline and Turquoise
The similarities of tourmaline and turquoise include:- Tourmaline and turquoise both streak white.
- Tourmaline's rarity is similar to turquoise.
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.Summary of Turquoise
Turquoise is a mineral that is a blue to greenish-blue color, often with veins or web-like patterns of darker color running through it. It is a relatively soft mineral, with a Mohs hardness of between 5 and 6, and has been used for decorative purposes for thousands of years. One of the most famous sources of turquoise is the Southwest United States, particularly Arizona and New Mexico, but it can also be found in other parts of the world, such as Iran, Afghanistan, and China.Table Comparison of Tourmaline vs Turquoise
| Tourmaline (src) | Turquoise (src) | |
|---|---|---|
| Transparency | transparent, translucent, opaque | translucent, opaque |
| Chemical Formula | (Ca,K,Na)(Al,Fe,Li,Mg,Mn)3(Al,Cr,Fe,V)6(BO3)3(Si,Al,B)6O18(OH,F)4 | CuAl6(PO4)4(OH)8• 4H2O |
| Chemical Composition | boron silicate | copper aluminum phosphate |
| Specific Gravity | 2.82, 3.9 | 2.4, 2.6, 2.84, 2.9, 2.9 |
| Hardness | 7, 7.5 | 5, 6 |
| Streak | white | white |
| Crystallography | hexagonal, trigonal | triclinic |
| Refractive Index | 1.603, 1.82 | 1.59, 1.65 |
| Hydrous | No | Yes |
| Colors | common: red sometimes: blue, black less common: gray, pink, brown, green, white, orange, purple, violet, yellow, colorless, multicolor |
common: blue, green less common: pale, turquoise, gray, multicolor |
| Category | cyclosilicate | phosphate |
| Birefringence | δ = -0.018 to −0.040 | δ = +0.040 |
| Fracture | conchoidal, uneven | conchoidal, uneven |