earth science

Larvikite

Larvikite 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 Larvikite rather than just read about it. In short: Larvikite is an igneous rock, specifically a variety of monzonite, notable for the presence of thumbnail-sized crystals of feldspar. These feldspars are known as ternary because they contain significant components of all three endmember feldspars.

Key takeaways

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

Reference excerpt

Larvikite is an igneous rock, specifically a variety of monzonite, notable for the presence of thumbnail-sized crystals of feldspar. These feldspars are known as ternary because they contain significant components of all three endmember feldspars. The feldspar has partly unmixed on the micro-scale to form a perthite, and the presence of the alternating alkali feldspar and plagioclase layers give its characteristic silver-blue schiller effect (called labradorescence) on polished surfaces. Olivine can be present along with apatite, and locally quartz. Larvikite is usually rich in titanium, with titanaugite and/or titanomagnetite present. Larvikite occurs in the Larvik Batholith (also called the Larvik Plutonic Complex), a suite of ten igneous plutons emplaced in the Oslo Rift (Oslo Graben) surrounded by ~1.1 billion year old Sveconorwegian gneisses. The Larvik Batholith is of Permian age, about 292–298 million years old. Larvikite is also found in the Killala Lake Alkalic Rock Complex near Thunder Bay in Ontario, Canada. The name originates from the town of Larvik in Norway, where this type of igneous rock is found. Many quarries exploit larvikite in the vicinity of Larvik.

Formation Intrusions of larvikite in Norway form part of the suite of igneous rocks that were emplaced during the Permian period, associated with the formation of the Oslo Rift. The crystallisation of a ternary feldspar indicates that this rock began to crystallise under lower crustal conditions.

Uses Larvikite is prized for its high polish and the labradorescence of its feldspar crystals, and is used as dimension stone, often cladding the facades of commercial buildings and corporate headquarters. It is known informally as Blue Pearl Granite, although this is not an accurate description. Larvikite has been designated by the International Union of Geological Sciences as a Global Heritage Stone Resource.

References

External links

Petrogenesis of the Oslo Region Larvikites and Associated Rocks (abstract) Journal of Petrology, 1980, volume 21, Number 3, pages 499-531 Structure of the larvikite-lardalite complex, Oslo-region, Norway, and its evolution (abstract) International Journal of Earth Sciences, 1978, volume 67, number 1, pages 330-342

Illustrations

Worked examples

Example 1 — a first encounter with Larvikite

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

In research: Larvikite 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 Larvikite 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: Larvikite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Building stone, Geology of Norway, Larvik, so understanding it makes those chapters shorter.
In everyday life: Look for Larvikite 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 Larvikite in 20 minutes

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

Frequently asked questions

What is Larvikite in simple terms?

Why does Larvikite 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 Larvikite?

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 Larvikite.