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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