Question

Silver is present in (a) galena (b) magnetite (c) dolomite (d) limonite

Short answer

Silver is present in galena.

Step-by-step solution

Analyze the Question

The question asks which of the given mineral ores contains silver. The options include galena, magnetite, dolomite, and limonite. Our task is to identify which of these has silver content.

Identify Silver-Bearing Ore

Galena is commonly known as a primary ore of lead, and it frequently contains silver as an impurity. While silver is not a major component of galena, it often contains enough silver to be mined as a source of silver.

Evaluate Other Options

Let's evaluate the other options: - Magnetite is primarily an iron ore and does not contain silver. - Dolomite is a mineral composed of calcium magnesium carbonate and is not a source of silver. - Limonite is an iron ore and similarly does not contain silver. Upon closer examination, none of these other options typically contain silver.

Conclusion Based on Analysis

Based on the evaluation of the mineral ores, only galena can contain silver as a notable component. Therefore, it is the correct answer to the question.

Key concepts

Galena

Galena is a fascinating mineral that is primarily associated with lead and possesses a shiny metallic luster owing to its lead content. It appears in a bright silver-gray color, making it visually distinct and easy to identify. More so, galena crystals are often cubic in shape, which further helps in identification.
One of the most intriguing aspects of galena is its ability to contain trace amounts of silver. This occurs because silver can substitute for lead in the mineral's structure. Although silver is not the predominant element in galena, the small amounts are sometimes economically viable for silver mining:

• Galena might contain up to a few percent silver, making silver extraction worthwhile even when it is not abundant.
• The presence of silver impurities in galena has historical significance, contributing to some of the earliest silver mining ventures.
• When mining, the silver content of galena can enhance its economic value significantly.

Thus, galena's role as a primary source of lead, coupled with its silver-bearing potential, makes it an important mineral in resource extraction.

Mineral Identification

Mineral identification is crucial in geology as it helps determine the types of minerals present in ore deposits. This process employs physical and chemical tests to provide accurate results. Identifying minerals involves examining various properties:

• Color: Although color can be a clue, it is less reliable because many minerals can share similar hues.
• Streak: The true color of a mineral in its powdered form; obtained by rubbing it across an unglazed ceramic plate.
• Hardness: Measured using the Mohs scale, where talc has a hardness of 1 and diamond a hardness of 10.
• Luster: The quality of light reflection from a mineral's surface, which can be metallic or non-metallic.
• Crystal Form: The unique geometric shape of a mineral's crystals, such as the cubic form seen in galena.

By utilizing these properties, geologists can systematically identify minerals like galena and determine their composition. This identification process is foundational in ore analysis, leading to better understanding and utilization of mineral resources.

Ore Analysis

Ore analysis entails exploring the composition and commercial value of mineral deposits. It is a scientific process used by geologists and mining engineers to evaluate ores for economic extraction. The steps in ore analysis are:
A central focus of ore analysis is to determine the specific mineral content and the concentration of valuable elements, such as silver in galena. This involves several laboratory techniques:

• Elemental Analysis: Techniques such as X-ray fluorescence (XRF) help identify the elements present in an ore sample.
• Quantitative Analysis: Includes assays to measure the concentration of specific elements like silver, dictating the ore's quality and viability for mining.
• Sampling: Accurate samples ensure that the analysis represents the mineral's average composition across the deposit.

Through ore analysis, it becomes evident whether mining an ore is economically feasible. For galena, which can harbor silver, this analysis determines the potential for exploiting the mineral for both lead and silver extraction. Results from these analyses guide mining strategies and economic planning, ensuring efficient and profitable extraction of resources.