In coal classification, a very hard coal grade containing very little volatile matter is called what?

Introduction / Context:
Questions on coal types are common in general science and geography because coal is still an important fossil fuel and industrial raw material. Different grades of coal vary in hardness, carbon content, and volatile matter, and each type has different uses and environmental impacts. This question focuses on identifying the name given to the hardest type of coal that contains very little volatile matter and a very high percentage of fixed carbon.

Given Data / Assumptions:

• The question is about a very hard coal that has low volatile matter content.
• The options include Anthracite and several unrelated geological terms like loess, atoll, and lava.
• We assume standard geological classification of coal: peat, lignite, bituminous coal, and anthracite.
• The focus is on the coal grade with the highest rank and hardness in this series.

Concept / Approach:
Coal ranks are based on how much pressure and heat the original plant material has experienced during coalification. As rank increases from peat to lignite to bituminous coal and finally to anthracite, the percentage of fixed carbon increases and the amount of volatile matter generally decreases. Anthracite is the highest rank of coal. It is very hard, shiny, burns with a short blue flame, and has high carbon content with very little volatile matter. Loess is a wind deposited fine silt, atoll is a ring shaped coral island, and lava is molten rock from volcanoes, so they are not coal at all.

Step-by-Step Solution:
1. Recall the common sequence of coal types: peat, lignite, bituminous coal, and anthracite.2. Understand that as coal rank increases, fixed carbon content increases and volatile matter content decreases.3. Recognise that anthracite is known as hard coal because of its hardness, high lustre, and high fixed carbon.4. Note that loess is a wind blown deposit, atoll is a coral island, and lava is molten rock, so none of these are coal grades.5. Match the description a hard coal containing little volatile matter with anthracite.6. Therefore, the correct answer is anthracite.

Verification / Alternative check:
Textbooks on geography and geology describe anthracite as the highest grade of coal that has more than about 90 percent fixed carbon and very low volatile content. It burns cleanly with little smoke and is used in specialised industrial processes and for domestic heating where available. Bituminous coal, by contrast, has more volatile matter and is softer. Loess, atoll, and lava appear in discussions of landforms, not fossil fuels. These standard descriptions confirm that anthracite is the correct match for the question description.

Why Other Options Are Wrong:
Option A, loess, is incorrect because it is a fine grained wind deposited sediment and not a type of coal. Option C, atoll, is a ring shaped coral reef and has nothing to do with coal classification. Option D, lava, is the molten or solidified rock from volcanic eruptions and is unrelated to fossil fuels. None of these terms refer to hard coal with low volatile matter.

Common Pitfalls:
Students sometimes confuse bituminous coal with anthracite because both are used as solid fuels and both are darker and harder than lignite. A useful memory aid is that anthracite is the last stage and is sometimes called hard coal or high rank coal. Another pitfall is to pick the unfamiliar term at random without remembering coal rank order. Learning the standard sequence from peat to anthracite helps avoid guessing and improves accuracy in related questions.

Final Answer:
A very hard coal grade that contains very little volatile matter is called anthracite.