Most circle earrings are completely sterling silver or sterling silver plated with gold. But some are a base metal, which depends on company, and then plated with gold. Most generally the plated base metal earrings are costume and not very valuable.
Yes, a circle is in fact composed of a degree or angle.
It is composed mostly of nickel and iron.
water
Sperm
Chromosomes are composed mostly of proteins and DNA.
No, it is mostly composed in strophic and modified strophic forms.
The crust is composed mainly of alumino-silicates.
Ocean
No but it is composed of them- mostly gases.
heart tissue
They weigh about 3.8 ounces.
Mostly south, but the Arctic Circle does cross through parts of it.