AllMineralsRock
Amethyst Vs. Topaz
Amethyst is a very popular gemstone composed of silicon dioxide.[1] Topaz is also a very popular gemstone and its chemical composition is aluminum silicate.[2]
Quick Facts on Differences of Amethyst and Topaz
For a quick recap of the differences amethyst and topaz:- While both amethyst and topaz can be translucent or transparent, topaz can be opaque.
- In terms of crystallography, amethyst can be hexagonal or trigonal while topaz is orthorhombic.
- For chemical formulas, amethyst is SiO2 while topaz can be Al2SiO4(F or OH)2.
- Amethyst streaks white while topaz streaks colorless.
- Amethyst can be commonly purple while topaz can be commonly blue, brown, pink, red or yellow.
- Amethyst's rarity is less rare than topaz.
- Amethyst's hardness is lower than topaz - amethyst is 7 and topaz is 8 on the Moh's scale.
- Amethyst's specific gravity is lower than topaz - amethyst is 2.651 and topaz ranges from 3.5 to 3.51.
Quick Facts on Similarities of Amethyst and Topaz
The similarities of amethyst and topaz include:- In terms of luster, amethyst and topaz both are vitreous.
Summary of Amethyst
Amethyst is a mineral that belongs to the quartz family and is known for its purple color. The color of amethyst can range from pale lilac to deep purple, depending on the concentration of iron and other trace elements present in the crystal. It is a popular gemstone and is often used for jewelry, decorative purposes, and spiritual healing.Summary of Topaz
Topaz is a mineral that belongs to the silicate family. It is a popular gemstone, renowned for its beautiful colors and excellent clarity. Topaz is commonly found in many locations around the world, including Brazil, Russia, Sri Lanka, and the United States. It is a hard mineral, with a Mohs hardness scale rating of 8. This makes it an ideal gemstone for use in jewelry, as it is resistant to scratches and wear and tear.Table Comparison of Amethyst vs Topaz
| Amethyst (src) | Topaz (src) | |
|---|---|---|
| Transparency | transparent, translucent | transparent, translucent, opaque |
| Chemical Formula | SiO2 | Al2SiO4(F,OH)2 |
| Chemical Composition | silicon dioxide | aluminum silicate |
| Specific Gravity | 2.651 | 3.5, 3.51, 3.53, 3.54, 3.56, 3.56, 3.57, 3.57 |
| Hardness | 7 | 8 |
| Streak | white | colorless |
| Crystallography | hexagonal, trigonal | orthorhombic |
| Refractive Index | 1.544, 1.553 | 1.607, 1.649 |
| Hydrous | No | No |
| Colors | common: purple sometimes: lilac less common: pale, violet, red |
common: pink, red, blue, brown, yellow sometimes: green less common: tan, gray, pale, beige, white, orange, purple, colorless, multicolor |
| Category | silicate | nesosilicate |
| Birefringence | δ = +0.009 (B-G interval) | δ = 0.010 |
| Fracture | conchoidal, uneven | conchoidal, subconchoidal |