earth science

Thomsonite

Thomsonite 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 Thomsonite rather than just read about it. In short: Thomsonite is the name of a series of tectosilicate minerals of the zeolite group. Prior to 1997, thomsonite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named thomsonite-Ca and thomsonite-Sr.

Key takeaways

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

Reference excerpt

Thomsonite is the name of a series of tectosilicate minerals of the zeolite group. Prior to 1997, thomsonite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named thomsonite-Ca and thomsonite-Sr. Thomsonite-Ca, by far the more common of the two, is a hydrous sodium, calcium and aluminium silicate, NaCa2Al5Si5O20·6H2O. Strontium can substitute for the calcium and the appropriate species name depends on the dominant element. The species are visually indistinguishable and the series name thomsonite is used whenever testing has not been performed. Globally, thomsonite is one of the rarer zeolites. Thomsonite was first identified in material from Scotland in 1820. It is named for the Scottish chemist Thomas Thomson. The crystal system of thomsonite is orthorhombic. The Mohs hardness is 5 to 5.5. It is transparent to translucent and has a density of 2.3 to 2.4. It may be colorless, white, beige, or somewhat green, yellow, or red. The crystals tend to be long thin blades that typically form radial aggregates, and sometimes fans and tufts. The aggregates are variable and may be spikey in appearance, dense and ball-like, or form worm-like growths. Tight acicular radiating clusters and sphericules are common forms. Thomsonite occurs with other zeolites in the amygdaloidal cavities of basaltic volcanic rocks, and occasionally in granitic pegmatites. Examples have been found in Faroe Islands (var. Faroelite), Scotland, Arkansas, Colorado, Michigan, Minnesota, New Jersey, Oregon, Ontario, Nova Scotia, Gujarat (India), and the Ural Mountains (Russia). Nodules of massive thomsonite that display an attractive banded coloring are found along the shore of Lake Superior. Most of these thomsonite nodules and their derived pebbles are less than 0.6 cm (1/4 inch). Those enclosed in basalt are extremely difficult to remove without breaking them. Consequently, a very large percentage of those used as gemstones are from pebbles collected from beaches.

References

Mindat Thomsonite-Ca Webmineral Thomsonite-Ca IMA Zeolite Classification R. V. Dietrich, Thomsonite

External links

Structure type THO

Illustrations

Worked examples

Example 1 — a first encounter with Thomsonite

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

In research: Thomsonite 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 Thomsonite 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: Thomsonite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Minerals described in 1820, Minerals in space group 52, Orthorhombic minerals, so understanding it makes those chapters shorter.
In everyday life: Look for Thomsonite 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Thomsonite in 20 minutes

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

Frequently asked questions

What is Thomsonite in simple terms?

Why does Thomsonite 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 Thomsonite?

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 Thomsonite.