What element is it that gives amethyst its violet color?

What element is it that gives amethyst its violet color?

Amethyst is a purple variety of quartz (SiO2) and owes its violet color to irradiation, iron impurities (in some cases in conjunction with transition element impurities), and the presence of trace elements, which result in complex crystal lattice substitutions.

Why can’t you tickle yourself?

Our studies at University College London have shown that the cerebellum can predict sensations when your own movement causes them but not when someone else does. When you try to tickle yourself, the cerebellum predicts the sensation and this prediction is used to cancel the response of other brain areas to the tickle.

Where does uncle sam name come from?

The origin of the term Uncle Sam, though disputed, is usually associated with a businessman from Troy, N.Y., Samuel Wilson, known affectionately as “Uncle Sam” Wilson. The barrels of beef that he supplied the army during the War of 1812 were stamped “U.S.” to indicate government property.

What was the first bird to be domesticated by man?

The goose was the first bird to be domesticated by man. An ancient story tells how a flock of white geese raised the alarm when Rome was attacked by the Gauls, and thus saved the city.

How much does a gallon of 2 percent milk weigh?

This is because a gallon of milk weighs about 8.6 pounds, give or take, based upon whether it is whole milk (heavier) or skim (lighter). But for our purposes, the 8.6 and 11.63 are accurate enough.

Can turtles talk?

Turtles don’t have vocal cords and their ears are internal, so scientists believed that turtles were deaf and didn’t communicate through sounds. However, research has found that turtles actually communicate at an extremely low frequency that sounds like “clicks, clucks, and hoots” that can only be heard through a hydrophone (a microphone used underwater). These sounds even come from the egg before the turtle hatches. Researchers hypothesize that this helps all the turtle siblings hatch at once.

Do dogs get cavities in their teeth?

Pets, like their human owners, can get cavities. However, cavities are relatively rare in dogs because dogs’ diets generally are not high in decay-causing sugars. Veterinary dental experts have noticed a mild rise in the incidence of cavities among dogs fed sugary treats.

Why does aluminum foil hurt your teeth?

Biting on aluminum foil can be painful and is usually noticed if you have metal in your mouth from dental work (e.g. fillings, crowns). Basically, when you bite on foil, you set up a battery in your mouth and the electrical current stimulates nerve endings in your tooth.