astronomy

Polar Star Diamond

Polar Star Diamond is a astronomy 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 Polar Star Diamond rather than just read about it. In short: The Polar Star diamond is a 41.28 carat brilliant cushion-cut diamond, from the Golconda region in India. Its lower pavilion is arranged as an eight-pointed star, hence its name, from Polaris, the Northern Star.

Key takeaways

Polar Star Diamond belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Polar Star Diamond to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Polar Star Diamond from memory before moving on to harder problems.

Reference excerpt

The Polar Star diamond is a 41.28 carat brilliant cushion-cut diamond, from the Golconda region in India. Its lower pavilion is arranged as an eight-pointed star, hence its name, from Polaris, the Northern Star. It is claimed that "the symmetry of the cut is so precise that it can be balanced on its culet" It is a rare type IIa diamond, meaning that it contains no nitrogen or boron. It is likely D or E color ("colourless"), with a trace of pink, and has blue fluorescence.

History The first record of the diamond's existence is around 1806 when it was owned by Joseph Bonaparte (eldest brother of Napoleon), who is reported to have purchased it from Morton for 52,500 francs. It is likely that he disposed of the diamond after abdicating and around the time of his settlement in the United States. It was bought in the 1820s by the Yusupov family (probably by Princess Tatiana Yusupov, wife of Prince Nikolai Borisovich Yusupov), whereby it passed to Prince Felix Yusupov, participant in the assassination of Rasputin. After the Russian Revolution, Yusupov and his family fled, taking the Polar Star, along with other gems such as La Pelegrina, the Sultan of Morocco and the Ram's head. To help sustain his family in exile, he sold the diamond to Cartier in 1924, who in turn sold the diamond in 1928 to Lady Deterding, the wife of the oil magnate Sir Henri Deterding, founder of Royal Dutch Shell. Following instructions from her will, Christie's auctioned the 'Polar Star' in Geneva on the 20 November 1980. It was bought by a Sri Lankan jeweller, Razeen Salih for 8 million Swiss Francs ($4.6 million) for the gem, which at the time was a record. The record was acknowledged by the Guinness Book of World Records, as the highest price per carat for a diamond at the time. Mr Salih's and his partner Sheikha Mahdi's company Mujoharat Al Sharq, in Jeddah purchased the 'Polar Star' for a client said to be a senior Saudi Arabian finance industry official.

Worked examples

Example 1 — a first encounter with Polar Star Diamond

Start with the simplest possible case. Write down what Polar Star Diamond claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 Polar Star Diamond 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 Polar Star Diamond 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 Polar Star Diamond

In research: Polar Star Diamond appears in astronomy 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 Polar Star Diamond 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: Polar Star Diamond is common in secondary-school and first-year university syllabi. It links to neighbouring topics Diamonds originating in India, Individual diamonds, Mineralogy stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Polar Star Diamond 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 Polar Star Diamond in 20 minutes

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

Frequently asked questions

What is Polar Star Diamond in simple terms?

Why does Polar Star Diamond matter?

Because it connects several astronomy 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 Polar Star Diamond?

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 Polar Star Diamond.