earth science

Mimetite

Mimetite 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 Mimetite rather than just read about it. In short: Mimetite is a lead arsenate chloride mineral (Pb5(AsO4)3Cl) which forms as a secondary mineral in lead deposits, usually by the oxidation of galena and arsenopyrite. The name derives from the Greek Μιμητής mimetes, meaning "imitator" and refers to mimetite's resemblance to the mineral pyromorphite.

Key takeaways

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

Reference excerpt

Mimetite is a lead arsenate chloride mineral (Pb5(AsO4)3Cl) which forms as a secondary mineral in lead deposits, usually by the oxidation of galena and arsenopyrite. The name derives from the Greek Μιμητής mimetes, meaning "imitator" and refers to mimetite's resemblance to the mineral pyromorphite. This resemblance is not coincidental, as mimetite forms a mineral series with pyromorphite (Pb5(PO4)3Cl) and with vanadinite (Pb5(VO4)3Cl). Notable occurrences are Mapimi, Durango, Mexico, and Tsumeb, Namibia.

Properties

Mimetite typically forms short hexagonal crystals that are yellow to brown to orange in color, very brittle, moderately hard (Mohs hardness 3.5–4), and dense (specific gravity 7.24). It is distinctive for its lack of transparency, its resinous to adamantine luster, and its solubility in nitric acid. Mimetite forms a complete solid solution series with pyromorphite, with phosphate (PO3−4) substituting for arsenate (AsO3−4). The two minerals are almost identical in their properties and can be difficult to distinguish except by laboratory tests. Pyromorphite is the more common mineral at most locales. Campylite is a name applied to mimetite or pyromorphite that crystallizes as distinctive barrel-shaped crystals forming curved hemispherical aggregates. Bellite is a name formerly applied to a chromium-bearing mimetite, or possibly a mixture of crocoite, mimetite, and quartz, which forms attractive orange red crystals, but has been discredited as a distinct mineral species.

Occurrences Mimetite is found in association with lead and arsenic minerals, including pyromorphite, cerussite, hemimorphite, smithsonite, vanadinite, anglesite, pyrite, mottramite, willemite, and wulfenite. Good specimens have been reported from Gila County, Arizona, US; Ojocaliente, Zacatecas, Mexico; Cumberland, England; Johanngeorgenstadt, Saxony, Germany; Namibia; and Broken Hill, Australia.

Mimetite specimen gallery

References

External links

"Mimetite" . Encyclopædia Britannica. Vol. 18 (11th ed.). 1911. Mineral Galleries

Illustrations

Worked examples

Example 1 — a first encounter with Mimetite

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

In research: Mimetite 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 Mimetite 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: Mimetite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Arsenate minerals, Halide minerals, Hexagonal minerals, so understanding it makes those chapters shorter.
In everyday life: Look for Mimetite 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 Mimetite in 20 minutes

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

Frequently asked questions

What is Mimetite in simple terms?

Why does Mimetite 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 Mimetite?

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 Mimetite.