earth science

Quintinite

Quintinite is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Quintinite rather than just read about it. In short: Quintinite is a carbonate mineral with the chemical formula Mg4Al2(OH)12CO3⋅3H2O. The mineral was named after Quintin Wight of Ottawa, Ontario, Canada (b. 1935), who was a significant contributor to mineral studies at Mont Saint-Hilaire.

Key takeaways

Quintinite belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Quintinite to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Quintinite from memory before moving on to harder problems.

Reference excerpt

Quintinite is a carbonate mineral with the chemical formula Mg4Al2(OH)12CO3⋅3H2O. The mineral was named after Quintin Wight of Ottawa, Ontario, Canada (b. 1935), who was a significant contributor to mineral studies at Mont Saint-Hilaire. Quintinite is found as 2H and 3T, or 2-hexagonal and 3-trigonal, polytypes, which were originally approved as separate species, but have not been considered species since 1998. These hexagonal and trigonal forms of quintinite are both from the hexagonal crystal systems, meaning they both have similar lengths of their crystal axes and the same angles between these axes. As a hexagonal mineral, quintinite has three axes of equal length at 60 degree angles to one another and a c axis perpendicular to these three axes of a different length. 2H occurs in carbonatite at Jacupiranga, São Paulo, Brazil, in the Jacupiranga mine and 3T occurs with minerals like gonnardite and donnayite. Both polytypes occur in hydrothermal vents in alkaline rocks. Herg (1977) interpreted the Jacupiranga area as related to a hotspot. The 3T polytype was originally found in the Poudrette quarry at Mont Saint-Hilaire, which is a rare alkaline intrusive complex. The 2H polytype is pleochroic, meaning that the mineral changes colors (in this case yellow and light yellow) when viewed at different angles under a polarizing petrographic microscope. The 3T polytype, however, is not commonly pleochroic but can show green pleochroism if it is high in iron. The 3T polytype has a positive index of refraction whereas the 2H polytype can possess crystals with either a positive or a negative index of refraction.

References

Illustrations

Worked examples

Example 1 — a first encounter with Quintinite

Start with the simplest possible case. Write down what Quintinite claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Quintinite before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Quintinite ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Quintinite

In research: Quintinite appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Quintinite in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Quintinite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aluminium minerals, Carbonate minerals, Hexagonal minerals, so understanding it makes those chapters shorter.
In everyday life: Look for Quintinite outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Quintinite in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Quintinite means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Quintinite out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Quintinite in simple terms?

Why does Quintinite matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Quintinite?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Quintinite.