earth science

Gyrolite

Gyrolite 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 Gyrolite rather than just read about it. In short: Gyrolite, NaCa16(Si23Al)O60(OH)8·14H2O, is a rare silicate mineral (basic sodium calcium silicate hydrate: N-C-S-H, in cement chemist notation) belonging to the class of phyllosilicates. Gyrolite is also often associated with zeolites.

Key takeaways

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

Reference excerpt

Gyrolite, NaCa16(Si23Al)O60(OH)8·14H2O, is a rare silicate mineral (basic sodium calcium silicate hydrate: N-C-S-H, in cement chemist notation) belonging to the class of phyllosilicates. Gyrolite is also often associated with zeolites. It is most commonly found as spherical or radial formations in hydrothermally altered basalt and basaltic tuffs. These formations can be glassy, dull or fibrous in appearance. Gyrolite is also known as centrallasite, glimmer zeolite or gurolite.

Discovery and natural occurrence

It was first described in 1851 for an occurrence at The Storr on the Isle of Skye, Scotland and is named from the ancient Greek word for circle, guros (γῦρος), based on the round form in which it is commonly found. Minerals associated with gyrolite include apophyllite, okenite and many of the other zeolites. Gyrolite is found in Scotland, Ireland; Italy, Faroe Islands, Greenland, India, Japan, USA, Canada and various other localities.

Occurrence in hardened cement paste and concrete Gyrolite is also mentioned as a rare calcium silicate hydrate (C-S-H) phase in cement chemistry textbooks with a simplified formulation: Ca8(Si4O10)3(OH)4 · ~6 H2O, which is consistent with the general formulation given here above, but does not consider the isomorphic substitution of one silicon atom by one aluminum and one sodium atoms in its crystal lattice. Gyrolite may form at higher temperature in oilwell cement muds containing ground granulated blast furnace slags (GGBFS) activated by alkali. It could also form in CEM III cement-based concrete exposed to alkali-silica reaction (ASR) at elevated temperature.

Hydrothermal synthesis Gyrolite can be synthesized in the laboratory, or industrially, by hydrothermal reaction in the temperature range 150 – 250 °C by reacting CaO and amorphous SiO2, or quartz, in saturated steam in the presence of CaSO4 salts or not. At temperature lower than 150 °C, the reaction rate is very slow. At temperature above 250 °C, gyrolite recrystallizes into 1.13 nm tobermorite and xonotlite. Gyrolite is also one of the rare phases detected in situ along with pectolite by synchrotron X-rays diffraction in hydrothermal synthesis of cement. Synthetic gyrolite has also a large specific surface and could enter industrial applications as oil absorber. Gyrolite globular rosettes resemble that of shlykovite, a new natural crystalline C-S-H mineral characterized in 2010 and also to mountainite and rhodesite, other crystalline ASR products of the same family.

Illustrations

Worked examples

Example 1 — a first encounter with Gyrolite

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

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

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

Frequently asked questions

What is Gyrolite in simple terms?

Why does Gyrolite 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 Gyrolite?

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 Gyrolite.