OF QUARTZ by nuhman10

VIEWS: 15 PAGES: 6

									Background

      Quartz is a silicon dioxide (SiO2). It consists of one Silicon atom and

two Oxygen atoms. It has no cleavage, a hardness of seven, and a

trigonal crystal system. Quartz is easy to find and it is the most common

mineral in the world. It can be found in almost all geological

environments, and most types of rocks consist of quartz. There are

different varieties of quartz such as milky quartz, rose quartz, smoky

quartz, amethyst, citrine, and rock crystal. All these varieties of quartz

are macrocrystalline, meaning they have large crystals. Some

microscopic varieties of quartz are typically called agates.

      Milky quartz is a variety of quartz that is described as white and

cloudy. The fact that this type of quartz is cloudy is the reason why it has

been named milky quartz. This cloudy nature comes from foreign

microscopic substances that have been trapped within the crystal since

the crystal first began to grow. Many lovely samples of gold have been

found within milky white quartz veins.

      Rose quartz is a type of quartz that has a range of color that varies

from pink to rose-red. This display of color is due to titanium and iron.

Rose quartz can be found in places such as Germany, Madagascar, Brazil,

India, and different locations in the US. Much of the world’s top quality

rose quartz is from Brazil.
      Smoky quartz is a variety of quartz that varies in color from brown

to black. At times it can even be a gray color. It is thought that smoky

quartz gets its color from being exposed to radiation. There are different

types of smoky quartz such as morion, cairngorm, and coon tail quartz.

Morion is a type of smoky quartz that is a deep black opaque color.

Cairngorm has its name because it is from Scotland’s Cairngorm

Mountains. Coon tail quartz is a variety of smoky quartz that is named for

its black and gray bands that resemble a raccoon’s tail. Some sources of

smoky quartz are the U.S., the Swiss Alps, and Brazil.

      Amethyst, a well-known gemstone, is the purple variety of quartz.

Amethyst is the Greek word for “not drunken” this is probably because

the Greeks used to believe that amethyst would mollify alcoholic excess.

Amethyst is also February’s birthstone. Since the color purple usually

represents royalty, amethyst has been worn by the wealthy and high in

power from the past to the present.

      Citrine is a yellow and orange variety of quartz that happens to be

fairly rare. Smoky quartz and amethyst are usually heated at high

temperatures to make citrine. Citrine is also the birthstone for November.

      If you see quartz that is clear, then it is a variety called rock

crystal. Rock crystal is the mineral used to make the famous fortune-
telling crystal balls. The highest quality of rock crystal has been found in

England, Brazil, the U.S., and Switzerland.




Problem

      Will heating various quartz samples turn them into citrine? I

hypothesized that if amethyst is heated it will lose its purple color and

turn yellow. Therefore I will attempt to turn amethyst into citrine. I

heated samples of milky quartz and rock crystal to see what effect it

would have on them also. Could there possibly be a change in mass by

heating the quartz samples?




Methods

      While testing my hypothesis I placed my samples on fire bricks, and

I used tongs to take them in and out of the high temperature furnace. I

wore goggles at all times to ensure my safety. To begin my experiment I

weighed the four quartz samples on a three-decimal digital balance. Two

of the samples were amethyst, the third was rock crystal, and the last was

milky quartz. When the furnace reached 800℉, I put all four samples on

fire bricks and placed them in the high temperature furnace at 10:52am.

The samples heated for 2 hours and 32 minutes. Then they were taken

out at 1:24pm and laid out to cool for 20 minutes. Again I weighed all four
quartz samples after they were heated and had time to cool off. I decided

to try my experiment again the next day to see whether or not I would

achieve different results. So I weighed four more quartz samples, again

two being amethyst, the third being rock crystal, and the fourth being

milky quartz. Then I placed the samples in the furnace set for 800℉ and

11:10am. The samples cooked in the furnace for 1 hour and 56 minutes.

Then I took them out at 1:06pm and let them cool this time for 30 minutes.

I weighed and recorded the mass of the second set of quartz samples after

they had heated to see if there was a change in mass.




Results

      These are the masses I recorded when I weighed the quartz

samples before and after they were heated.

                                 1st Test
    Quartz Sample             Before Heating            After Heating
Amethyst (round)                  9.548 g                  5.801 g
Amethyst (long)                   4.415 g                  4.395 g
Rock Crystal                     12.375 g                 12.372 g
Milky Quartz                     23.792 g                 23.727 g

                                 2nd Test
    Quartz Sample             Before Heating            After Heating
Amethyst (round)                  4.053 g                  2.485 g
Amethyst (long)                   2.645 g                  2.478 g
Rock Crystal                     14.105 g                 14.086 g
Milky Quartz                     13.125 g                 12.569 g
      One of the reasons there was such a drastic mass change in the

round amethyst is because both times a small piece broke off from each

one while they were cooking in the furnace. Also on the last heating the

milky quartz had multiple crystals that broke apart while in the furnace.

This is why the mass change was greater compared to the other samples

after they were heated. During the first test, when I heated the four

quartz samples the two amethysts lost their purple color and turned green.

The milky quartz had an orange color, however, there was no change of

color with the rock crystal. Then I decided to do a second test. This time

only the long amethyst lost its purple color and turned green, while the

round amethyst remained purple. There was also no change in color with

the milky quartz or rock crystal.




Conclusion

      In conclusion, I think that I achieved better results the first time

because I let the quartz samples cook longer than the second time. During

the first test I let the samples cook for 2 hours and 32 minutes and I found

that the amethyst lost its color and turned green. Also the milky quartz

had an orange color which is the color of citrine. I decided to do a second

test to see if the outcome would be the same or different. During the

second test I let the samples cook for an hour and 56 minutes and only
one of the four samples changed color. The long amethyst turned green.

So therefore, I was successful in producing citrine the first time, but my

hypothesis was that I could produce citrine from amethyst. Instead I

produced citrine from milky quartz.

								
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