Mineral Quiz: Test Your Geology Knowledge

Color is the least reliable way to identify a mineral because many minerals can occur in a variety of colors. The same mineral can have different colors due to impurities or variations in its chemical composition. Additionally, some minerals can have the same color, making it difficult to differentiate between them based on color alone. Therefore, relying solely on color to identify a mineral may lead to inaccurate conclusions. Other properties such as streak, hardness, and luster are more reliable indicators of a mineral's identity.

The property being showcased in the picture is streak. Streak refers to the color of a mineral's powder when it is rubbed against a rough surface. It is different from the mineral's external color. By observing the streak, one can determine the mineral's true color.

Silky, waxy, and vitreous are terms used to describe the luster of a mineral. Luster refers to the way light reflects off the surface of a mineral. Silky luster describes a mineral with a smooth and fibrous appearance, waxy luster refers to a mineral that appears smooth and has a wax-like sheen, while vitreous luster describes a mineral with a glassy and shiny appearance. Therefore, these terms are used to describe the different types of luster that minerals can exhibit.

A mineral with a hardness of 7 is considered to be harder than Apatite, which has a hardness of 5 on the Mohs scale. According to the Mohs scale, a mineral can scratch any mineral with a lower hardness than itself. Therefore, the mineral with a hardness of 7 will be able to scratch the Apatite, resulting in the given answer.

The mineral that nearly ruined your day is Quartz. The description of the mineral, including its uneven and chunky shape indicating fracture, its ability to leave a white streak on the streak plate, and its ability to scratch the window, all point towards Quartz. Additionally, the glassy luster mentioned after cleaning off the mineral is another characteristic of Quartz.

Silica is commonly used to make glass because it has a high melting point and can be easily molded into different shapes. It also has a low coefficient of thermal expansion, making it resistant to thermal shock. Additionally, silica provides transparency to the glass, allowing light to pass through. These properties make silica an ideal mineral for manufacturing glass products.

This mineral shows the property of cleavage, which means that it can break along specific planes or directions. Cleavage is a characteristic of minerals that have a crystalline structure and is determined by the arrangement of atoms within the mineral. When a mineral with cleavage is broken, it will break along smooth, flat surfaces. This property is useful in identifying minerals and can help determine their crystal structure and composition.

Atoms arranged in a specific pattern will form a crystal. A crystal is a solid material whose atoms or molecules are arranged in a highly ordered, repeating pattern extending in all three spatial dimensions. This regular arrangement of atoms gives crystals their characteristic shape and properties, such as their symmetry and cleavage. Crystals can be found naturally in minerals or can be artificially synthesized.

The property demonstrated in the picture is fracture. Fracture refers to the way a mineral breaks when it is not along a cleavage plane. In the picture, the mineral appears to have a rough and irregular break, indicating that it does not have a distinct cleavage. This suggests that the mineral has a fracture property.

Gypsum is a soft mineral that can be easily scratched with a fingernail. It has a hardness of 2 on the Mohs scale, which means it is relatively soft compared to other minerals. This characteristic makes it easy to identify gypsum by conducting a simple scratch test with a fingernail.

Minerals may form on Earth's surface when solutions evaporate. When solutions containing dissolved minerals are exposed to heat or dry conditions, the water in the solution evaporates, leaving behind the solid minerals. As the water evaporates, the concentration of minerals in the solution increases, causing them to precipitate and form solid crystals. This process is commonly observed in areas with high evaporation rates, such as salt flats or desert regions, where minerals like salt or gypsum can be found. Crystallization being delayed, magma heating a solution, or the presence of pure metals do not directly contribute to the formation of minerals through evaporation.