earth science

Ye'elimite

Ye'elimite 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 Ye'elimite rather than just read about it. In short: Ye'elimite is the naturally occurring form of anhydrous calcium sulfoaluminate, Ca4(AlO2)6SO4. It gets its name from Har Ye'elim in Israel in the Hatrurim Basin west of the Dead Sea where it was first found in nature by Shulamit Gross, an Israeli mineralogist and geologist who studied the Hatrurim Formation.

Key takeaways

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

Reference excerpt

Ye'elimite is the naturally occurring form of anhydrous calcium sulfoaluminate, Ca4(AlO2)6SO4. It gets its name from Har Ye'elim in Israel in the Hatrurim Basin west of the Dead Sea where it was first found in nature by Shulamit Gross, an Israeli mineralogist and geologist who studied the Hatrurim Formation. The mineral is cubic, with 16 formula units per unit cell, and a cell dimension of 1.8392 nm, and is readily detected and quantified in mixtures by powder x-ray diffraction.

Occurrence in cement It is alternatively called "Klein's Compound", after Alexander Klein of the University of California, Berkeley, who experimented with sulfoaluminate cements around 1960, although it was first described in 1957 by Ragozina. Ye'elimite is most commonly encountered as a constituent of sulfoaluminate cements, in which it is manufactured on the million-tonne-per-annum scale. It also occasionally occurs adventitiously in Portland-type cements. It is thus an anhydrous mineral of the cement clinker whose idealized oxide formula 4CaO·3Al2O3·SO3 is also written C4A3S̅ in the cement chemist notation (CCN). On hydration in the presence of calcium and sulfate ions, it forms the insoluble, fibrous mineral ettringite, which provides the strength in sulfoaluminate concretes, monosulfoaluminate, and aluminium hydroxide. It is manufactured by heating the appropriate quantities of finely-ground alumina, calcium carbonate and calcium sulfate to between 1100 and 1300 °C, preferably in the presence of small quantities of fluxing materials, such as Fe2O3. On heating above 1350 °C, ye'elimite begins to decompose to tricalcium aluminate, calcium oxide, sulfur dioxide and oxygen.

See also Other rare minerals also discovered in the Hatrurim Formation: Brownmillerite (Ca2(Al,Fe)2O5) Gehlenite (Ca2Al[AlSiO7]) Other phases also present in the cement clinker: Larnite: calcium olivine (Ca2SiO4, C2S, or belite) Mayenite (Ca12Al14O32[☐4Cl2]) Calcium aluminates: Monocalcium aluminate (CA) Tricalcium aluminate (C3A) Dodecacalcium hepta-aluminate (C12A7) Calcium aluminate cements

References

Illustrations

Worked examples

Example 1 — a first encounter with Ye'elimite

Start with the simplest possible case. Write down what Ye'elimite 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 Ye'elimite 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 Ye'elimite 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 Ye'elimite

In research: Ye'elimite 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 Ye'elimite 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: Ye'elimite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aluminates, Aluminium minerals, Calcium minerals, so understanding it makes those chapters shorter.
In everyday life: Look for Ye'elimite 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 Ye'elimite in 20 minutes

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

Frequently asked questions

What is Ye'elimite in simple terms?

Why does Ye'elimite 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 Ye'elimite?

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 Ye'elimite.