earth science

Nuummite

Nuummite 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 Nuummite rather than just read about it. In short: Nuummite is a rare metamorphic rock that consists of the amphibole minerals gedrite and anthophyllite. It is named after the area of Nuuk in Greenland, where it was found.

Key takeaways

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

Reference excerpt

Nuummite is a rare metamorphic rock that consists of the amphibole minerals gedrite and anthophyllite. It is named after the area of Nuuk in Greenland, where it was found.

Description

Nuummite, usually black in colour and opaque, consists of two amphiboles, gedrite and anthophyllite, which form exsolution lamellae that give the rock its typical iridescence. Other common minerals in the rock are pyrite, pyrrhotite and chalcopyrite, which form shimmering yellow bands in polished specimens. In Greenland the rock formed due to two consecutive metamorphic overprints of an originally igneous rock. The intrusion took place in the Archean around 2800 million years ago, the metamorphic overprints have been dated at 2700 and 2500 million years ago.

History The rock was first discovered in 1810 in Greenland by the mineralogist K. L. Giesecke. It was defined scientifically by O. B. Bøggild between 1905 and 1924. In 2009, a new variety of nuummite was discovered in central Mauritania. Under its unofficial name Jenakite, this variety is distinctive due to the presence and high density of blue and green anthophyllite needle-like crystals. It has no golden anthophyllite needle-like crystals. Nuummite from Greenland predominantly has golden and occasionally blue anthophyllite needle-like crystals.

References

Further reading P. W. U. Appel & A. Jensen: A new gem material from Greenland: iridescent orthoamphibole [nuummite]. Gems and Gemology, 23, P. 3642, 1987 (Online Extract[link removed]) K. A. Rodgers et al.: Iridescent anthophyllite-gedrite from Simiuttat, Nuuk district, southern West Greenland. Composition, exsolution, age. Mineralogical Magazine, Vol. 60, P. 937–947, December 1996 (Online Extract)

Illustrations

Worked examples

Example 1 — a first encounter with Nuummite

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

In research: Nuummite 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 Nuummite 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: Nuummite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Gemstones, Metamorphic rocks, Mineral stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Nuummite 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 Nuummite in 20 minutes

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

Frequently asked questions

What is Nuummite in simple terms?

Nuummite is a rare metamorphic rock that consists of the amphibole minerals gedrite and anthophyllite. It is named after the area of Nuuk in Greenland, where it was found.

Why does Nuummite 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 Nuummite?

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 Nuummite.