earth science

Tobermorite

Tobermorite 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 Tobermorite rather than just read about it. In short: Tobermorite is a calcium silicate hydrate mineral with chemical formula: Ca5Si6O16(OH)2·4H2O or Ca5Si6(O,OH)18·5H2O. Two structural varieties are distinguished: tobermorite-11 Å and tobermorite-14 Å.

Key takeaways

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

Reference excerpt

Tobermorite is a calcium silicate hydrate mineral with chemical formula: Ca5Si6O16(OH)2·4H2O or Ca5Si6(O,OH)18·5H2O. Two structural varieties are distinguished: tobermorite-11 Å and tobermorite-14 Å. Tobermorite occurs in hydrated cement paste and can be found in nature as an alteration mineral in metamorphosed limestone and in skarn. It has been reported to occur in the Maqarin Area of north Jordan and in the Crestmore Quarry near Crestmore Heights, Riverside County, California. Tobermorite was first described in 1880 for an occurrence in Scotland, on the Isle of Mull, around the locality of Tobermory.

Use in Roman concrete Aluminum-substituted tobermorite is understood to be a key ingredient responsible for the longevity of ancient undersea Roman concrete. The volcanic ash that Romans used for construction of sea walls contained phillipsite, and an interaction with sea water caused the crystalline structures in the concrete to expand and strengthen, making that material substantially more durable than modern concrete when exposed to sea water.

Cement chemistry

Tobermorite is often used in thermodynamical calculations to represent the pole of the most evolved calcium silicate hydrate (C-S-H). According to its chemical formula, its atomic Ca/Si or molar CaO/SiO2 (C/S) ratio is 5/6 (0.83). Jennite represents the less evolved pole with a C/S ratio of 1.50 (9/6).

See also Other calcium silicate hydrate (C-S-H) minerals: Afwillite – Nesosilicate alteration mineral also sometimes found in hydrated cement paste Gyrolite – Rare phyllosilicate mineral crystallizing in small spheres Jaffeite – Sorosilicate mineral Jennite – Inosilicate alteration mineral in metamorphosed limestone and in skarn Okenite – Phyllosilicate mineral Thaumasite – Complex calcium silicate hydrate mineral Xonotlite – Calcium inosilicate mineral Other calcium aluminium silicate hydrate, (C-A-S-H) minerals: Hydrogarnet Hydrogrossular Hydrotalcite Katoite Tacharanite (Ca12Al2Si18O33(OH)36)

References

Illustrations

Worked examples

Example 1 — a first encounter with Tobermorite

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

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

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

Frequently asked questions

What is Tobermorite in simple terms?

Why does Tobermorite 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 Tobermorite?

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 Tobermorite.