AllMineralsRock
Agate Vs. Quartz
Agate is a very popular gemstone composed of silicon dioxide.[1] Quartz is also a very popular gemstone and its chemical composition is also silicon dioxide.[2]
Quick Facts on Differences of Agate and Quartz
For a quick recap of the differences agate and quartz:- While both agate and quartz can be commonly red, agate is often white and quartz is often yellow.
- Agate's specific gravity is lower than quartz - agate ranges from 2.6 to 2.64 and quartz ranges from 2.651 to 2.91.
Quick Facts on Similarities of Agate and Quartz
The similarities of agate and quartz include:- Agate and quartz both can be opaque, translucent or transparent.
- In terms of crystallography, agate and quartz both can be hexagonal or trigonal.
- For chemical formulas, agate and quartz both are SiO2.
- In terms of luster, agate and quartz both can be greasy, vitreous or waxy.
- Agate and quartz both streak white.
- Agate's rarity is similar to quartz.
- Agate's hardness overlaps with quartz - agate ranges from 6.5 to 7 and quartz is 7 on the Moh's scale.
Summary of Agate
Agate is a mineral that belongs to the quartz family. It is typically found in volcanic rocks and is characterized by its banded appearance, which is caused by the deposition of different minerals in layers. The mineral is identified by its hardness, which ranges from 6.5 to 7 on the Mohs scale, and its translucent to opaque appearance. While agate is typically associated with shades of brown and gray, it can also be found in a variety of colors, including blue, green, pink, purple, and red.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.Table Comparison of Agate vs Quartz
| Agate (src) | Quartz (src) | |
|---|---|---|
| Transparency | transparent, translucent, opaque | transparent, translucent, opaque |
| Chemical Formula | SiO2 | SiO2 |
| Chemical Composition | silicon dioxide | silicon dioxide |
| Specific Gravity | 2.6, 2.64 | 2.651, 2.91 |
| Hardness | 6.5, 7 | 7 |
| Streak | white | white |
| Crystallography | hexagonal, trigonal | hexagonal, trigonal |
| Refractive Index | 1.53, 1.543 | 1.544, 1.553 |
| Hydrous | No | No |
| Colors | common: red, white sometimes: blue, gray, pink, black, brown, green, banded, orange, purple, yellow, multicolor |
common: red, yellow sometimes: blue, gray, pink, black, brown, green, white, orange, purple, violet, colorless, multicolor |
| Category | chalcedony | silicate |
| Fracture | conchoidal, uneven | conchoidal, uneven |