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.

Can you eat eggs after the expiration date?

According to the Food Safety and Inspection Service of the U.S. Department of Agriculture, eggs in the shell will maintain freshness for three to five weeks beyond the carton’s stamped expiration date, provided that you keep them refrigerated at a temperature of about 40 degrees Fahrenheit.

How many friends are you allowed to have on Facebook?

5,000. What’s more is that the 5,000 friend limit is not just for friends – it’s for connections in general. Every person can have a maximum of 5,000 connections on Facebook, which include both friends and Pages. You will not be able to accept incoming friend requests or like any more Pages if you get to that number.

Why does Aspirin help during a heart attack?

Platelets are cells that clump together and help to form blood clots. Aspirin keeps platelets from clumping together, thus helping to prevent or reduce blood clots. During a heart attack. Blood clots form in an already-narrowed artery and block the flow of oxygen-rich blood to the heart muscle.

What height to reach terminal velocity?

A falling person will reach terminal velocity after about 12 seconds, falling some 450 m (about 1,500 ft) in that time. That person will not then fall any faster, so it makes no difference what distance they fall if it is more than 1,500 ft – they will still reach the ground at the same speed.

How many time zones are there in Alaska?

Alaska’s four time zones have become two. More than 98 percent of the state’s population is in one of these zones, now called Yukon time, which is one hour earlier than Pacific standard time and four hours earlier than Eastern standard time.

Do frogs have ears?

Frogs can hear both in the air and below water. They do not have external ears; the eardrums (tympanic membranes) are directly exposed or may be covered by a layer of skin and are visible as a circular area just behind the eye.

What does the word Taser stand for?

Taser is actually not a word, but an acronym for a fictional weapon: Thomas A. Swift’s Electric Rifle. Cover added the “A” to Tom Swift’s name. The original character did not have a middle name. Victor Appleton is the author of the Tom Swift books.