What is a mineral and how do you know if it’s a rock or a mineral? Well many people mistake rocks for minerals but there are some things you need to know to find out if you have a mineral. People mistake rocks for minerals but there is one comparison between them. Rocks are made of minerals but minerals aren’t made of rocks. There are four questions you should ask yourself to see if you really have a mineral in your hands. First, Is it a solid? Second, Is it formed in nature? Third, Is it made of non-living material? Finally, Does it have a crystalline structure (inner crystal structure)? Now that you know these four questions you can discover if you have a mineral or just a plain old rock.

There are many different types of minerals in the world. There are many different types of Opal such as Common Opal, Precious Opal, Fire Opal, and Wood Opal. Common Opal is translucent and sometimes pale in other various colors, but doesn’t have the reflective colors that precious opal has. Precious Opal can be a milky white or black in color with reflections of bright colors such as blues, reds, and yellows. Fire Opal is red and yellow in color and has flame like reflections almost like fire. Wood Opal is wood that has been partially taken up by Opal.

Most interesting about Opal is that when warmed in your hand the water contained within the mineral can change the appearance color making brilliant colors. Opal is also used to make some different rings and other types of jewelry. Every mineral is classified into a group of some kind Opal is classified in the Silicates Quartz group. Also every mineral is devised of chemicals which would be a chemical formula. Opals chemical formula would be SIO2 H2O. Opal can be found in certain places around the world such as Tabergs mines, Nordmark, Varmland, Mosgruvan, and Vastmanland.

There are many ways to identify a mineral using many different methods. Some methods are very useful to identifying a mineral but others aren’t very useful because weathering or something else effects how they could be classified.

In 1822, Friedrich Moh who was a German mineralogist devised a practical way of comparing the hardness or scratch resistance of minerals. Today, this has become universally known as Moh’s Hardness Scale. Moh’s Hardness Scale works by Moh took ten well-known available minerals and arranged them in order of their scratch hardness. To discover the hardness of your mineral you take one of the ten reference minerals. If the reference mineral scratches your mineral it’s harder than your mineral. Keep trying to scratch the mineral going down each time until that reference mineral cannot scratch your mineral. Opal is rated a 5.5-6.5 on the scale.

Color becomes a part in identifying minerals also. All minerals come in different shades and colors. One mineral can come in a variety of colors. Depending on the impurities contained inside of the mineral the mineral can be any color. But beside impurities other things can also change the color of minerals. Weathering also effects minerals and can change the appearance of minerals. These factors weathering and impurities make color not a reliable way to identify a mineral. Opal is either colorless to white. Sometimes even bluish black or red. Precious varieties have a rainbow color.

Luster is the way a surface reflects light. Luster appears in minerals like when minerals are shiny or dull looking. When you say that you mean the way light reflects off the surface. Minerals can have metallic, submetallic, and nonmetallic luster. If a mineral were dull its luster would either be a submetallic or a nonmetallic luster. But if a mineral were shiny its luster would be metallic. Opals luster is a greasy looking reflection. It’s not quite shiny but it has a greasy looking luster.

In order to find a mineral’s streak what you do is the mineral has to be rubbed against a piece of unglazed porcelain or streak plate. When you do this the powder from the mineral ends up on the streak plate. The color on the plate is not always the same color as the mineral. For example an Opals streak is white even though it can be blue, black, or red. The steak is not affected by weather so this makes it more reliable to identify a mineral.

There are two types of breaks that minerals can have either cleavage or fracture. Cleavage is the tendency of some minerals to break along flat surfaces and fracture is when some minerals to break along a curved or irregular surface. Opal has no cleavage it has the fracture type of chonchoidal. So Opal usually is broken on a curved or irregular surfaces. This is also a good way to identify minerals but some may have the same type of a break of cleavage or fracture.

Density is the measure of how much matter there is in a given amount of space. Density is also another way to identify the difference between minerals. Density is usually measured in grams per cubic centimeters. In order to determine a mineral’s density what you do is you fill a graduated cylinder with water. Then you drop a certain mineral in it and however much the water level goes up that is your density of the mineral. Opal has a density of 1.9 to 2.5.

Some minerals have certain special properties ranging from fluorescence, chemical reactions, taste, optical properties, and magnetism. These properties may vary in different minerals depending on what mineral you own. Opal doesn’t have many special properties but it’s fluorescence in UV light, insoluble or it can’t be dissolved in acids, it deteriorates when heated and it may even turn into Quartz, And it’s also sensitive against dehydration in which it can become fragile and develop some fractures.

Well you’ve now reached the end of my report. I hope you liked it and learned as much about my mineral as I have throughout this project. So to sum it all up who ever reads it I hope you enjoyed it and will use the information in my report for further use in the future.