earth science

Panethite

Panethite 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 Panethite rather than just read about it. In short: Panethite, chemical formula (Na,Ca)2(Mg,Fe)2(PO4)2, is a rare phosphate mineral that was only found in one meteorite on Earth. It was originally found in the Dayton meteorite in Ohio.

Key takeaways

Panethite 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 Panethite to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Panethite from memory before moving on to harder problems.

Reference excerpt

Panethite, chemical formula (Na,Ca)2(Mg,Fe)2(PO4)2, is a rare phosphate mineral that was only found in one meteorite on Earth. It was originally found in the Dayton meteorite in Ohio. It is classified as H-M symbol (2/m) with space group of P21/n. It is amber in color. It was named in the honor of Friedrich Adolf Paneth (1887–1958), a German chemist who made many contributions toward the discovery of the origin of the universe, and especially studies of meteorites.

Structure Using X-ray diffraction, the unit cell and the space group parameters were determined. The strongest lines of the X-ray were 5.10(6), 3.236(5), 3.007(10), 2.749, 2.710(7) (American Mineralogist, 509). But the error of the cell lengths were relatively high due to twinning and some disorder in the grains examined. Panethite has a monoclinic crystal system with a0=10.18 ±0.01Å, b0=14.90 ±0.02Å, c0=25.87 ±0.03Å and β =91.1˚, and its space group P21/n. Within the error that accompanied the microprobe analysis, the X-ray density was found to be 2.99g/ml.

Properties Both brianite and panethite were clear and transparent with no crystal faces; and neither present any discernible cleavage. Panethite is a biaxial negative, pale amber in its color and the estimated 2V was approximated to be 51˚. The refractive indices are α=1.567, β=1.576, γ = 1.579 all ±0.001 (Fuchs, 1967). Even though panethite lacks the lamellar structure that brianite shows, panethite shows simple twinning. The higher refractive indices along with the lamellae structure of brianite help us to distinguish these two minerals apart under the microscope. The specific gravity of panethite was between 2.90 and 3.0. Both minerals were insoluble in water. Panethite and brianite are the minerals known to have the greatest amount of sodium content in meteorites (Fuchs, 1967). Panethite was named after the then director of the Max Planck Institute for Chemistry, Mainz, Germany, Friedrich Adolf Paneth (1887-1958).

Worked examples

Example 1 — a first encounter with Panethite

Start with the simplest possible case. Write down what Panethite 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 Panethite 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 Panethite 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 Panethite

In research: Panethite 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 Panethite 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: Panethite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Meteorite minerals, Minerals in space group 14, Monoclinic minerals, so understanding it makes those chapters shorter.
In everyday life: Look for Panethite 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 Panethite in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Panethite 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 Panethite out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Panethite in simple terms?

Panethite, chemical formula (Na,Ca)2(Mg,Fe)2(PO4)2, is a rare phosphate mineral that was only found in one meteorite on Earth. It was originally found in the Dayton meteorite in Ohio.

Why does Panethite 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 Panethite?

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 Panethite.