Minerology Quiz By Raghu

Explanation
Peridote is the gem variety of olivine. Olivine is a mineral that belongs to the silicate group and is typically found in igneous rocks. Peridote is a transparent green gemstone that is formed from olivine. It is known for its vibrant green color and is often used in jewelry. Ruby, Emerald, and Amethyst are all different gemstones and not varieties of olivine.

Explanation
The correct answer is 2:7. This means that the ratio of soro silicates is 2 parts to 7 parts. In other words, for every 2 parts of one type of soro silicate, there are 7 parts of another type. This ratio indicates the relative proportions of the two types of soro silicates in a mixture or compound.

Explanation
Firestone is another name for Flint. Flint is a type of hard stone that is commonly used to make tools and weapons. It is known for its ability to produce sparks when struck against steel, making it useful for starting fires. While Opal, Agate, and Onyx are also types of stones, they are not synonymous with Firestone.

Explanation
Monazite is not a mineral because it is a group of phosphate minerals, rather than a specific mineral itself. It is a rare earth phosphate mineral that typically contains thorium, uranium, and other rare earth elements. Hedenbergite, Fayalite, and Pseudotachylite are all examples of minerals, each with their own distinct chemical composition and crystal structure.

Explanation
Diamond crystallizes in a cubic structure. This means that its atoms are arranged in a regular, repeating pattern with equal distances between them in all directions. The cubic structure is characterized by a high degree of symmetry, with three equal axes intersecting at right angles. This arrangement of atoms gives diamond its unique properties, such as its hardness and ability to refract light.

Explanation
Quartz is the correct answer because it is a mineral that does not have cleavage. Cleavage refers to the tendency of a mineral to break along planes of weakness, producing smooth, flat surfaces. Quartz, on the other hand, breaks with a conchoidal fracture, which means it breaks in a curved, shell-like manner, without producing flat surfaces. This lack of cleavage is one of the distinguishing characteristics of quartz.

Explanation
Tridymite is a correct answer for this question because it is a mineral that forms in a scaly structure. It is a high-temperature polymorph of silica and is commonly found in volcanic rocks. Tridymite has a unique crystal structure that consists of three-dimensional networks of linked tetrahedra, giving it a scaly appearance. It is often colorless or white and can be translucent or opaque. Tridymite is commonly found in association with other minerals in igneous rocks and can also be found in some metamorphic and sedimentary rocks.

Explanation
The given zone symbol is 001 because it is the only one that satisfies the condition of being a tautozonal face. A tautozonal face is a face that contains the same set of zone axes as the zone itself. In this case, the zone symbol 001 has the same set of zone axes as the given zone symbol 100 and 110, making it a tautozonal face.

Explanation
Amorphous substances are characterized by a lack of long-range order in their atomic structure, resulting in a disordered arrangement of atoms. This lack of symmetry in their structure leads to variations in their physical properties, such as refractive index and electrical conductivity, in different directions. Therefore, amorphous substances are considered anisotropic, meaning their properties vary depending on the direction of measurement.

Explanation
The correct answer is "All the above" because optical sign can indeed be determined by all three materials mentioned - quartz plate, gypsum plate, and mica. These materials have different optical properties and can be used in various optical devices to determine the sign of the light, such as in polarizers or waveplates. Quartz plate has a positive optical sign, gypsum plate has a negative optical sign, and mica can have both positive and negative signs depending on its orientation.