A period is a bleed from the womb (uterus) that is released through the vagina. It happens approximately every 28 days, although anywhere between 24 and 35 days is common. Periods can begin when girls are between 8 and 16 years old, but usually start around the age of 12.
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5â8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor.
Featured Gems. According to legend, Vikings used iolite slices to reduce glare when checking the sunâs position. Emerald is the bluish green to green variety of beryl, a mineral species that includes aquamarine. Named after seawater, aquamarineâs fresh watery hue is a cool plunge into a refreshing pool. Fireworks.