Meyrowitzite

Key takeaways

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

Reference excerpt

Meyrowitzite, Ca(UO2)(CO3)2·5H2O, is a carbonate mineral verified in May of 2018 by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association. It is an extremely rare mineral, discovered in the Markey mine Utah, U.S.A. The mineral is a transparent yellow and has blades up to approximately 0.2 mm in length. It is soluble in water or aqueous solutions. Meyrowitzite is named in honor of Robert Meyrowitz (1916–2013), an American analytical chemist. After serving in WW II, he joined the United States Geological Survey (USGS). He was known for developing innovative new methods for analyzing small and difficult to study mineralogical samples along with his formulation of the high-index immersion liquids.

Occurrence Meyrowitzite was discovered underground in the Markey mine, Red Canyon, Suan Juan County, Utah, U.S.A. It has not been found in any other location. Mineralized channels of meyrowitzite are in the Shinarump Member of the Chinle Formation. The Shinarump member is made up of medium-to coarse-grained sandstone, conglomeratic sandstone beds, and thick siltstone lenses. Ore minerals were deposited as replacements of wood and other organic materials and as disseminations in the enclosing sandstone. Since the closing of the Markey mine, oxidation of primary ores in the humid underground environment has produced a variety of secondary minerals. These secondary minerals are primarily sulfates as efflorescent crusts on the surfaces of mine walls. It is found on calcite-veined asphaltum in association with gypsum, markeyite, and rozenite.

Properties Meyrowitzite has bladed crystals with a length up to about 0.2 mm. The blades are commonly irregular and radiating outward from a central point. Blades are elongate on [010], flattened on {100} and exhibit the forms {100}, {001}, {101}, {110}, and {011}. There was no twinning observed. It is a transparent yellow with vitreous luster and a very pale yellow streak. It displays variable fluorescence from weak greenish-yellow to moderate greenish blue under a 405 nm laser. It has a hardness of 2 based on Mohs hardness scale. It has brittle tenacity, irregular fracture, and one perfect cleavage on {-101}. The density was measured at 2.70(2) g*cm^-3 by flotation in a methylene iodide and toluene mixture. It is easily soluble in room temperature water. It is optically biaxial (+) with α = 1.520(2), β = 1.528(2), and γ = 1.561(2) measured in white light. The 2V measured using extinction data analyzed with EXCALIBRW is 53.0(6)°; the calculated 2V is 53.3°. The dispersion is weak, r > v. The optical orientation is Z = b, Y ^ a ≈ 19° in obtuse β. Crystals are weakly pleochroic in shades of pale yellow, X ≈ Y < Z. The Gladstone–Dale compatibility, 1 – (KP/KC) is –0.039 (excellent) using the empirical formula, and –0.035 (excellent) using the ideal formula, where k(UO3) = 0.134.

Raman spectroscopy Raman spectroscopy is a method of chemical analysis that is non-destructive. The analysis provides detailed information about chemical structure, phase, polymorphy, crystallinity, and molecular interactions. Meyrowitzite's Raman spectroscopy was conducted on a Horiba XploRA PLUS. The spectrum was recorded using a 785 nm diode laser because of significant fluorescence when using a 532 nm diode laser. Meryrowitzites spectrum is similar to that of Zellerites. However, Meyrowitzite's spectrum has a larger number of bands primarily in the UO2+2. This is most likely due to the site-symmetry which for Meyrowitzite is monoclinic and orthorhombic for Zellerite.

Chemical analysis Chemical Analysis of Meyrowitzite was performed on a Cameca SX-50 electron microprobe with four wavelength-dispersive spectrometers and using Probe for EPMA software at the University of Utah. The acceleration voltage was 15 keV, with a 10 nA beam current, and a beam diameter of 5μm. The raw X-ray intensities were corrected with a φρ(z) algorithm for the matrix effect. The concentration of the total oxygen and carbon, calculated from the ideal formula, were used in the matrix correction. Because of crystal dehydration, the surfaces suffered and it was impossible to obtain a well-polished crystal surface. The sample was not damaged because of the beam. The H2O and (CO2) amounts were calculated based on the structure determination (2 C and 13 O apfu) due to insufficient material instead of the more common method of direct determination. The empirical formula is Ca0.94(U1.00O2)(CO3)2·5(H2.02O). The ideal formula is Ca(UO2)(CO3)2·5H2O, which requires CaO 10.78, UO3 54.98, CO2 16.92, and H2O 17.32, totaling 100 wt%.

X-Ray crystallography and structure determination Powder and single-crystal X-ray studies were performed using a Rigaku R-Axis Rapid II curved imaging plate microdiffractometer with monochromatized MoKα radiation. A Gandolfi-like motion was used during the powder study on the φ and ω axes. This was done to randomize the sample which was several crystals thick. Using the JADE 2010 software, d values and intensities were derived by profile fitting. Unit-cell parameters from the powder data using JADE 2010 are a = 12.417(17) Å, b = 16.127(17) Å, c = 20.123(17) Å, β = 107.53(4)°, and V = 3842(7) Å3. Meyrowitzite crystals are relatively poor-quality for single-crystal study. The crystal fragment, measuring 80 × 80 × 30 μm, exhibited substantial mosaicity, some spot streaking, and some extra spots indicative of one or more satellite crystals. This crystal provided usable data to a resolution of .88Å. Structural data were determined with Rigaku CrystalCleal software. This included Lorentz and polarization corrections, and the application of an empirical absorption correction using the multi-scan method with ABSCOR. Rigaku XPlain program determined the space group P21/n, which led to a structural solution using SIR2011. Because of the imperfect crystal fragment, numerous reflections violated the extinction conditions for space group P21/n (n glide) and the commission of five poorly fitting reflections that did not violate the extinction conditions. SHELXL-2013 was used for the refining of the structure. The limited data set allowed refinement with anisotropic displacement parameters for all fully occupied sites, but not for four approximately half-occupied H2O sites (OW14, OW15, OW16, and OW17). It also did not allow the location of H sites in difference Fourier maps.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Meyrowitzite

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

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

How to study Meyrowitzite in 20 minutes

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

Frequently asked questions

What is Meyrowitzite in simple terms?

Meyrowitzite, Ca(UO2)(CO3)2·5H2O, is a carbonate mineral verified in May of 2018 by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association. It is an extremely rare mineral, discovered in the Markey mine Utah, U.S.A.

Why does Meyrowitzite 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 Meyrowitzite?

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 Meyrowitzite.