Emerald and beryl - what's the difference?
To answer, we need to distinguish between two concepts - the mineral species and variety.
A mineral species is a group of minerals with a similar chemical composition and the same crystal structure.
Mineral varieties are minerals of a certain type and differing in their physicochemical properties or the composition of impurities.
Now back to our question. Beryl is a mineral species, belongs to the class of silicates and has the formula Al2 [Be3 (Si6O18)]. In connection with the possibility of entering into the structure of beryl various impurities, it has several varieties that differ in colors. One of them is an emerald, the green color of which is caused by the replacement of Al in the structure of beryl with Cr or V and Fe.
Aventurine is called a rock, which is a type of quartzite. It is characterized by a fine or fine-grained structure and mainly quartz composition. A distinctive feature of aventurine is the presence in it of numerous small inclusions of mica (most often) or hematite and chlorite (rarely), which create a sparkling effect when light hits the stone.