Mammothite

Key takeaways

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

Reference excerpt

Mammothite is a mineral found in the Mammoth mine in Tiger, Arizona and also in Laurium, Attika, Greece. This mineral was named in 1985 by Donald R. Peacor, Pete J. Dunn, G. Schnorrer-Köhler, and Richard A. Bideaux, for the Mammoth vein (one of the two main veins in the mine) and the town of Mammoth, Arizona, which was named for the mine. The mammothite that is found in Arizona exist as euhedral crystals imbedded in micro granular, white colored anglesite with a saccharoidal texture. The associated minerals include phosgenite, wulfenite, leadhillite and caledonite. In Greece, the mammothite exists as small euhedral crystals and also as microscopic rock cavities lined with projecting crystals within the slags. The associated minerals here are cerussite, phosgenite and matlockite. The ideal chemical formula for mammothite is Pb6Cu4AlSb5+O2(OH)16Cl4(SO4)2.

Occurrence Mammothite is associated with various minerals but different minerals at different locations. In the Mammoth mine in Tiger, Arizona this mineral is associated with phosgenite, wulfenite, leadhillite and caledonite. There are roughly 100 different kinds of mineral species in the Mammoth mine and about 25 of these are considered to be a part of an anomalous oxidized sequence. These minerals will grow in close quarters with each other but other minerals containing Pb, Cu, Fe, and Zn are also present. The minerals contained in this abnormal sequence contain Pb, Cu, SO4, and CO3 and they may occur in the same minerals. The element Antimony is a very rare element that is exhibited in mammothite but also in the mineral tetrahedrite, which is seen having small crystals that are attached to pyrite crystals. In Laurium, Attika, Greece, the mammothite exists as small euhedral crystals and also as microscopic rock cavities lined with projecting crystals within the slags. The associated minerals here are cerussite, phosgenite and matlockite.

Physical properties Mammothite is a cerulean blue to pale blue, transparent mineral with a resinous or subvitreous luster. It exhibits a hardness of 3 on the Mohs hardness scale. Mammothite occur as tabular to acicular crystals that exhibit radial aggregates. In Arizona, mammothite is mostly tabular but several samples are elongated on the [001] axis. In Tiger, Arizona, crystals are less than 1.0 mm in size. The density was difficult to be measured due to the small size and an abundance of other minerals attached to it. By using heavy liquid techniques, it was determined to be greater than 4.2g/cm3 but the idealized end member was calculated to be 5.25g/cm3. In Laurium, Greece, this mineral is different in appearance. The color of the samples may range from pale blue to white. The crystals in Greece are very small and can exhibit two habits. These habits include being prismatic and bladed; or being very prismatic and elongated on the [001] axis. Mammothite is brittle and shows distinct cleavage along the {010} plane. The measured density is 5.25 g/cm3.

Optical properties Mammothite is biaxial positive, which means it will refract light along two axes. It exhibits a 2V(measured)=80°, strong dispersion with r>v, and displays visible pleochroism with varying colors of shades of pale blue. The indices of refraction are α=1.868, β=1.892, γ=1.928. Mammothite is also transparent and does not respond to ultraviolet radiation.

Chemical properties The chemical formula for mammothite is Pb6Cu4AlSb5+O2(OH)16Cl4(SO4)2. Mammothite is one of the few minerals that has an Sb atom in the pentavalent state.

Chemical composition

This microprobe analyses was done on the mammothite from Tiger, Arizona. These crystals were analyzed by using an ARL-SEMQ electron microprobe that used an operating voltage of 15 kV and a sample current of 0.025 μA. The resulted values were then used to get the weight percentages of the sample of mammothite. However, samples of mammothite that were found in Greece were too small to be able to perform this same analyses. The Laurium samples were identified to be mammothite by using the X-ray diffraction method.

X-ray crystallography Mammothite is in the monoclinic crystal system, with space group C2. The unit cell dimensions are a=18.93(3) Å, b=7.33(1) Å, c=11.35(2) Å, β=112.44(10)°. These values were obtained through powder diffraction that was found by using a 114.6 mm diameter Gandolfi camera, CuKα X-radiation, polycrystalline sample and a silicon sample as an internal standard.

Illustrations

Worked examples

Example 1 — a first encounter with Mammothite

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

In research: Mammothite 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 Mammothite 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: Mammothite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Minerals described in 1985, Minerals in space group 5, Monoclinic minerals, so understanding it makes those chapters shorter.
In everyday life: Look for Mammothite 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.

How to study Mammothite in 20 minutes

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

Frequently asked questions

What is Mammothite in simple terms?

Mammothite is a mineral found in the Mammoth mine in Tiger, Arizona and also in Laurium, Attika, Greece. This mineral was named in 1985 by Donald R.

Why does Mammothite 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 Mammothite?

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 Mammothite.