earth science

Getchellite

Getchellite 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 Getchellite rather than just read about it. In short: Getchellite is a rare sulfide of arsenic and antimony, AsSbS3, that was discovered by B. G.

Key takeaways

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

Reference excerpt

Getchellite is a rare sulfide of arsenic and antimony, AsSbS3, that was discovered by B. G. Weissberg of the New Zealand Department of Scientific and Industrial Research in 1963, and approved as a new species by the International Mineralogical Association in 1965. Many metal sulfides are grey to black, but a few are brightly colored. Orpiment is yellow to brownish gold, cinnabar is deep red and getchellite is a bright orange red.

Thermal properties Getchellite turns darker red when heated, becoming black by the time it reaches its melting point. Close to this temperature it sublimes (changes directly from a solid to a vapor) and recrystallizes on cooler surfaces as minute acicular black crystals.Melting point: 340 °C to 355 °C. Boiling point: near 470 °C.

Structure Each of the semimetal atoms, arsenic and antimony, is bonded to three sulfur atoms to form a trigonal pyramid characteristic of elements in group V of the periodic table. These (As,Sb)S3 pyramids form 8-membered (As,Sb)8S8 rings which in turn combine to form sheets parallel to (001), with each sulfur atom bonded to two semimetal atoms. The occupancy of the metal sites is disordered, and within the sheets the 8-membered rings are orientated normal to the plane of the sheet. The sheet structure is responsible for the cleavage and twin planes of getchellite Unit cell a = 11.949 Å; b = 9.028 Å; c = 10.130 Å; β= 116.15°; V = 980.9 Å3; Z = 8. Space group P21/a.

Powder diffraction

Discovery In August 1962 Weissberg visited the Getchell mine at Adam Peak, about 32 km northeast of Golconda, in Humboldt County, Nevada, US. The purpose of his visit was to collect samples for a study of the relationship between various fairly common sulfides, not to look for new minerals. Getchellite was in some of the samples, but it was not discovered until the rocks were re-examined, a year later. The new mineral was named after the Getchell Mine, which in turn became the type locality. Samples from the mine are preserved as type material (a reference material for the mineral), at the Smithsonian National Museum of Natural History, Washington, D.C., US.

Environment At the type locality getchellite is found in an epithermal (formed at low temperature) arsenical gold deposit in a narrow, steeply dipping fault zone cutting across interbedded shales, argillites (lithified muds and oozes) and limestones, near an intrusion of granodiorite.Associated minerals are orpiment, realgar, stibnite, cinnabar and quartz, as well as galkhaite, laffittite, chabournéite, christite, lorandite, marcasite, barite, fluorite and calcite.

Distribution Getchellite is found at the type locality in Nevada, United States, and also in Azerbaijan, China, Iran, Japan, Kyrgyzstan and Russia.

Synthesis Getchellite has been synthesized from As3SbS6 glass in sodium sulfide solutions at 2600 C. and 1,000 bars pressure.

References

Illustrations

Worked examples

Example 1 — a first encounter with Getchellite

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

In research: Getchellite 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 Getchellite 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: Getchellite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antimony minerals, Arsenic minerals, Minerals in space group 14, so understanding it makes those chapters shorter.
In everyday life: Look for Getchellite 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 Getchellite in 20 minutes

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

Frequently asked questions

What is Getchellite in simple terms?

Getchellite is a rare sulfide of arsenic and antimony, AsSbS3, that was discovered by B. G.

Why does Getchellite 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 Getchellite?

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 Getchellite.