AllMineralsRock
Quartz Vs. Sapphire
Quartz is a very popular gemstone composed of silicon dioxide.[1] Sapphire is also a very popular gemstone and its chemical composition is also silicon dioxide.[2]
Quick Facts on Differences of Quartz and Sapphire
For a quick recap of the differences quartz and sapphire:- For chemical formulas, quartz is SiO2 while sapphire is Al2O3.
- While both quartz and sapphire can be vitreous, in terms of luster, quartz can be greasy or waxy and sapphire can be adamantine.
- Quartz streaks white while sapphire streaks colorless.
- Quartz can be commonly red or yellow while sapphire can be commonly blue or green.
- Quartz's rarity is less rare than sapphire.
- Quartz's hardness is lower than sapphire - quartz is 7 and sapphire is 9 on the Moh's scale.
- Quartz's specific gravity is lower than sapphire - quartz ranges from 2.651 to 2.91 and sapphire ranges from 3.99 to 4.
Quick Facts on Similarities of Quartz and Sapphire
The similarities of quartz and sapphire include:- Quartz and sapphire both can be opaque, translucent or transparent.
- In terms of crystallography, quartz and sapphire both can be hexagonal or trigonal.
Summary of Quartz
Quartz is a mineral that is composed of silicon and oxygen atoms arranged in a continuous framework of SiO4 silicon-oxygen tetrahedra. It is one of the most abundant minerals found in the Earth's crust. Quartz can be found in a variety of colors such as white, pink, purple, brown, gray, and black. It is also known for its unique crystal structure, which is hexagonal in shape, and its hardness, which is 7 on the Mohs scale.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.Table Comparison of Quartz vs Sapphire
| Quartz (src) | Sapphire (src) | |
|---|---|---|
| Transparency | transparent, translucent, opaque | transparent, translucent, opaque |
| Chemical Formula | SiO2 | Al2O3 |
| Chemical Composition | silicon dioxide | silicon dioxide |
| Specific Gravity | 2.651, 2.91 | 3.99, 4, 4.1 |
| Hardness | 7 | 9 |
| Streak | white | colorless |
| Crystallography | hexagonal, trigonal | hexagonal, trigonal |
| Refractive Index | 1.544, 1.553 | 1.757, 1.779 |
| Hydrous | No | No |
| Colors | common: red, yellow sometimes: blue, gray, pink, black, brown, green, white, orange, purple, violet, colorless, multicolor |
common: green, blue sometimes: pink, amber, yellow less common: gray, black, brown, white, orange, purple, violet, colorless, red, gold, multicolor |
| Solubility | Insoluble at STP | Insoluble |
| Fracture | conchoidal, uneven | conchoidal |