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.
Green emeralds have been a popular gemstone for centuries. The emerald is best known for its striking green color, which is as bold as it is beautiful. Green emeralds make a perfect center stone for a distinctive engagement ring. A Precious Gemstone, Emeralds Range In Hues From Yellow-Green To Blue-Green.