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.
Emerald is the gemstone name of the mineral beryl when it has a rich green color. It is the most popular stone from the beryl mineral group. Most emeralds have abundant inclusions and fractures.arnet is the name of a group of minerals with a common crystal structure, but variable composition. Most garnets are red, but the stone also occurs in orange, yellow, purple, green, pink, black, and other colors.