AllMineralsRock
Rhodonite Vs. Tourmaline
Rhodonite is a popular gemstone composed of manganese silicate.[1] Tourmaline is a very popular gemstone and its chemical composition is boron silicate.[2]
Quick Facts on Differences of Rhodonite and Tourmaline
For a quick recap of the differences rhodonite and tourmaline:- In terms of crystallography, rhodonite is triclinic while tourmaline can be hexagonal or trigonal.
- For chemical formulas, rhodonite is MnSiO3 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 rhodonite and tourmaline can be vitreous, in terms of luster, rhodonite can be dull or greasy.
- Rhodonite streaks colorless while tourmaline streaks white.
- While both rhodonite and tourmaline can be commonly red, rhodonite is often pink.
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Rhodonite's hardness is lower than tourmaline - rhodonite ranges from 5.5 to 6.5 and tourmaline ranges from 7 to 7.5 on the Moh's scale.
- Rhodonite can be scratched by quartz (7) while tourmaline can not be.
Quick Facts on Similarities of Rhodonite and Tourmaline
The similarities of rhodonite and tourmaline include:- Rhodonite and tourmaline both can be opaque, translucent or transparent.
- Rhodonite's rarity is similar to tourmaline.
- Rhodonite's specific gravity overlaps with tourmaline - rhodonite ranges from 3.57 to 3.67 and tourmaline ranges from 2.82 to 3.9.
Summary of Rhodonite
Rhodonite is a mineral that belongs to the pyroxenoid mineral group and is known for its distinctive pink color. It is often found in metamorphic rocks, especially in manganese-rich environments. It has a hardness of 5.5 to 6.5 on the Mohs scale and a specific gravity of 3.4 to 3.7. Rhodonite is named after the Greek word "rhodon," which means rose, in reference to its pink color.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 Rhodonite vs Tourmaline
| Rhodonite (src) | Tourmaline (src) | |
|---|---|---|
| Transparency | transparent, translucent, opaque | transparent, translucent, opaque |
| Chemical Formula | MnSiO3 | (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 | manganese silicate | boron silicate |
| Specific Gravity | 3.57, 3.67, 3.76 | 2.82, 3.9 |
| Hardness | 5.5, 6.5 | 7, 7.5 |
| Streak | colorless | white |
| Crystallography | triclinic | hexagonal, trigonal |
| Refractive Index | 1.711, 1.752 | 1.603, 1.82 |
| Hydrous | No | No |
| Colors | common: red, pink sometimes: rose less common: gray, black, yellow, brown |
common: red sometimes: blue, black less common: gray, pink, brown, green, white, orange, purple, violet, yellow, colorless, multicolor |
| Category | inosilicate | cyclosilicate |
| Birefringence | δ = 0.013 | δ = -0.018 to −0.040 |
| Fracture | conchoidal, hackly, uneven | conchoidal, uneven |