Olivine vs Quartz
Olivine and Quartz are commonly confused, and 3 measured properties separate them — crystal system most clearly.
Olivine vs Quartz
Olivine
(Mg,Fe)2SiO4
The green magnesium-iron silicate that makes up most of the upper mantle — the most abundant mineral inside the Earth.
Quartz
SiO2
The second most abundant mineral in the Earth's continental crust, and the reference point for hardness 7 on the Mohs scale.
| Property | Olivine | Quartz |
|---|---|---|
| Crystal system Categorical values can be listed side by side but not ordered or subtracted. | orthorhombic | trigonal |
| Density | 3.27–4.37 g/cm³ higher | 2.65–2.66 g/cm³ |
| Lustre Categorical values can be listed side by side but not ordered or subtracted. | vitreous | vitreous |
| Mohs hardness Mohs hardness is an ordinal scale: values can be ranked, but differences and ratios between them are not meaningful. | 6.5–7 | 7 higher |
| Streak Categorical values can be listed side by side but not ordered or subtracted. | white | white |
Why these get confused
both glassy and hard, but olivine is green and granular where quartz is colourless and forms prisms
The confusion is a real and documented one, not a resemblance we have invented.