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Thursday, February 21, 2019  
Eureka!
A non-discovery.

I’ve found my solution to my diminishing intake of my morning coffee.
A solution utilized by many other coffee drinkers but until now eluding me.
A solution suggested to me by my son on a visit with him in DUMBO, Brooklyn many years ago; that I peremptorily dismissed and forgot about.

In some unconscious manner, without a discernible reminder, the thought to add decaffeinated coffee beans to my morning brew percolated in my consciousness.
I rushed out to buy some beans and made my first blended regular and decaf coffee.
I found it delicious.
And instead of a miserly seven ounces I sucked down twelve ounces with great enthusiasm.
My breakfast has now returned to the civilized length that I’ve been used to.

I could worry about the why of my slow uptake.
But I’m where I want to be now and I’m fearful of what I may find if I investigate the why-it-took-so-long.
So,
A non-discovery.
Eureka!

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Tagging Today, Thursday, February 21, 2019
My 315th consecutive posting, committed to 5,000.

Time is 12.01am.
On Thursday, Boston’s temperature will reach a high of 46* with a feels-like temperature of 41*.

The increased temperature will last several days, a good turnout for the shoulder calendar; a good reason to drop the winter calendar and segue into the shoulder.

Dinner is out at a restaurant called Craigie on Main, in Cambridge, a place where I’ve been several times, all times leaving the place quite satisfied.

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Tick Tock
315 posts to date.
Today we’re at the 6.30% mark of my commitment, the commitment a different way of marking the passage of time.

5,000 posts will take 13.69 years, taking me to a new phase of my life.
Will see thirteen “Winter-Spring Shoulder Season Calendar, Feb 14 to April 7.”

This shoulder calendar features a panoply of weather conditions, from stormy winter to lovely spring, the latter somewhat rare.
Although the next several days will be hinting at spring, don’t expect a linear march to better weather.
Accept that many unpleasant days are lining up to annoy us.
For a while yet we will often be dressing for wintry weather.

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Question of the Day
Why diamonds?

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Elephant jokes to tell at a bar:
The patient tells her personal physician that she’s been seeing elephants hanging around her students.

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Gallery of Greenway Art
I took these photos a couple of weeks ago.
What a great resource for the city of Boston.

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Answer to Question
Why diamonds?

Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic.
At room temperature and pressure, another solid form of carbon known as graphite is the chemically stable form, but diamond almost never converts to it.

Diamond has the highest hardness and thermal conductivity of any natural material, properties that are utilized in major industrial applications such as cutting and polishing tools.
They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth.

Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions being boron and nitrogen).
Small numbers of defects or impurities (about one per million of lattice atoms) color diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, orange or red.
Diamond also has relatively high optical dispersion (ability to disperse light of different colors).

Most natural diamonds have ages between 1 billion and 3.5 billion years.
Most were formed at depths between 150 and 250 kilometers (93 and 155 mi) in the Earth's mantle, although a few have come from as deep as 800 kilometers (500 mi).
Under high pressure and temperature, carbon-containing fluids dissolved minerals and replaced them with diamonds.
Much more recently (tens to hundreds of million years ago), they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites.

Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gas by chemical vapor deposition (CVD).
Imitation diamonds can also be made out of materials such as cubic zirconia and silicon carbide. Natural, synthetic and imitation diamonds are most commonly distinguished using optical techniques or thermal conductivity measurements.

Hardness
The hardness of diamond contributes to its suitability as a gemstone.
Because it can only be scratched by other diamonds, it maintains its polish extremely well.
Unlike many other gems, it is well-suited to daily wear because of its resistance to scratching—perhaps contributing to its popularity as the preferred gem in engagement or wedding rings, which are often worn every day.

The hardest natural diamonds mostly originate from the Copeton and Bingara fields located in the New England area in New South Wales, Australia.
These diamonds are generally small, perfect to semiperfect octahedra, and are used to polish other diamonds.

Their hardness is associated with the crystal growth form, which is single-stage crystal growth. Most other diamonds show more evidence of multiple growth stages, which produce inclusions, flaws, and defect planes in the crystal lattice, all of which affect their hardness.
It is possible to treat regular diamonds under a combination of high pressure and high temperature to produce diamonds that are harder than the diamonds used in hardness gauges.

Color

Diamond has a wide bandgap of 5.5 eV corresponding to the deep ultraviolet wavelength of 225 nanometers.
This means that pure diamond should transmit visible light and appear as a clear colorless crystal.
Colors in diamond originate from lattice defects and impurities.

The diamond crystal lattice is exceptionally strong, and only atoms of nitrogen, boron and hydrogen can be introduced into diamond during the growth at significant concentrations (up to atomic percents).
Transition metals nickel and cobalt, which are commonly used for growth of synthetic diamond by high-pressure high-temperature techniques, have been detected in diamond as individual atoms; the maximum concentration is 0.01% for nickel and even less for cobalt.
Virtually any element can be introduced to diamond by ion implantation.

Nitrogen is by far the most common impurity found in gem diamonds and is responsible for the yellow and brown color in diamonds. Boron is responsible for the blue color.
Color in diamond has two additional sources: irradiation (usually by alpha particles), that causes the color in green diamonds, and plastic deformation of the diamond crystal lattice.

Plastic deformation is the cause of color in some brown and perhaps pink and red diamonds.

In order of increasing rarity, yellow diamond is followed by brown, colorless, then by blue, green, black, pink, orange, purple, and red.
"Black", or Carbonado, diamonds are not truly black, but rather contain numerous dark inclusions that give the gems their dark appearance.
Colored diamonds contain impurities or structural defects that cause the coloration, while pure or nearly pure diamonds are transparent and colorless.
Most diamond impurities replace a carbon atom in the crystal lattice, known as a carbon flaw. The most common impurity, nitrogen, causes a slight to intense yellow coloration depending upon the type and concentration of nitrogen present.
The Gemological Institute of America (GIA) classifies low saturation yellow and brown diamonds as diamonds in the normal color range, and applies a grading scale from "D" (colorless) to "Z" (light yellow). Diamonds of a different color, such as blue, are called fancy colored diamonds and fall under a different grading scale.

In 2008, the Wittelsbach Diamond, a 35.56-carat (7.112 g) blue diamond once belonging to the King of Spain, fetched over US$24 million at a Christie's auction.
In May 2009, a 7.03-carat (1.406 g) blue diamond fetched the highest price per carat ever paid for a diamond when it was sold at auction for 10.5 million Swiss francs (6.97 million euros, or US$9.5 million at the time).
That record was, however, beaten the same year: a 5-carat (1.0 g) vivid pink diamond was sold for $10.8 million in Hong Kong on December 1, 2009.

Clarity

Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called inclusions, and surface defects, called blemishes. Clarity is one of the four Cs of diamond grading, the others being carat, color, and cut.

Inclusions are solids, liquids, or gases that were trapped in a mineral as it formed.
They may be crystals of a foreign material or even another diamond crystal, or may have produced structural imperfections, such as tiny cracks that make a diamond appear whitish or cloudy.
The number, size, color, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond.
A clarity grade is assigned based on the overall appearance of the stone under ten times magnification, which is a magnification standard for loupes used in the gem world.

Most inclusions present in gem-quality diamonds do not affect the diamonds' performance or structural integrity and are not visible to the naked eyes.
However, large clouds can affect a diamond's ability to transmit and scatter light.
Large cracks close to or breaking the surface may reduce a diamond's resistance to fracture.

Diamonds with higher clarity grades are more valued, with the exceedingly rare "Flawless" graded diamond fetching the highest price.
Minor inclusions or blemishes are useful, as they can be used as unique identifying marks analogous to fingerprints.
In addition, as synthetic diamond technology improves and distinguishing between natural and synthetic diamonds becomes more difficult, inclusions or blemishes can be used as proof of natural origin.

Cut

A diamond cut is a style or design guide used when shaping a diamond for polishing such as the brilliant cut.
Cut does not refer to shape (pear, oval), but the symmetry, proportioning and polish of a diamond.
The cut of a diamond greatly affects a diamond's brilliance; this means if it is cut poorly, it will be less luminous.

In order to best use a diamond gemstone's material properties, a number of different diamond cuts have been developed.
A diamond cut constitutes a more or less symmetrical arrangement of facets, which together modify the shape and appearance of a diamond crystal.
Diamond cutters must consider several factors, such as the shape and size of the crystal, when choosing a cut.

The practical history of diamond cuts can be traced back to the Middle Ages, while their theoretical basis was not developed until the turn of the 20th century.
Design creation and innovation continue to the present day: new technology—notably laser cutting and computer-aided design—has enabled the development of cuts whose complexity, optical performance, and waste reduction were hitherto unthinkable.

The most popular of diamond cuts is the modern round brilliant, whose facet arrangements and proportions have been perfected by both mathematical and empirical analysis.
Also popular are the fancy cuts, which come in a variety of shapes, many of which were derived from the round brilliant.
A diamond's cut is evaluated by trained graders, with higher grades given to stones whose symmetry and proportions most closely match the particular "ideal" used as a benchmark.

The strictest standards are applied to the round brilliant; although its facet count is invariable, its proportions are not.
Different countries base their cut grading on different ideals: one may speak of the American Standard or the Scandinavian Standard (Scan. D.N.), to give but two examples.

Round brilliant

Developed ca. 1900, the round brilliant is the most popular cut given to diamond.
It is usually the best choice in terms of saleability, insurability (due to its relatively "safe" shape), and desired optics.

Facet count and names

The modern round brilliant (Figure 1 and 2) consists of 58 facets (or 57 if the culet is excluded); 33 on the crown (the top half above the middle or girdle of the stone) and 25 on the pavilion (the lower half below the girdle).
The girdle may be frosted, polished smooth, or faceted.
In recent decades, most girdles are faceted; many have 32, 64, 80, or 96 facets; these facets are excluded from the total facet count. Likewise, some diamonds may have small extra facets on the crown or pavilion that were created to remove surface imperfections during the diamond cutting process. Depending on their size and location, they may hurt the symmetry of the cut and are therefore considered during cut grading.

Figure 1 assumes that the "thick part of the girdle" is the same thickness at all 16 "thick parts". It does not consider the effects of indexed upper girdle facets.
Figure 2 is adapted from the Tolkowsky book, which was originally published in 1919. Since 1919, the lower girdle facets have become longer. As a result, the pavilion main facets have become narrower.

Proportions

While the facet count is standard, the actual proportions—crown height and crown angle, pavilion depth and pavilion angle, and table size—are not universally agreed upon.
There are at least six "ideal cuts" that have been devised over the years, but only three are in common use as a means of benchmarking.
Developed by Marcel Tolkowsky in 1919, the American Standard (also known as the American Ideal and Tolkowsky Brilliant) is the benchmark in North America. It was derived from mathematical calculations that considered both brilliance and fire.
The benchmark in Germany and other European countries is the Practical Fine Cut (German: Feinschliff der Praxis, also known as the Eppler Cut), introduced in 1939. It was developed in Germany by empirical observations and differs only slightly from the American Standard. Introduced as part of the Scandinavian Diamond Nomenclature (Scan. D. N.) in 1969, the Scandinavian Standard also differs very little.

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Good Morning on this Thursday, the 21th day of February..
We talked about blending decaf with regular coffee and the calendar and weather.
A tiny bit naughty elephant joke.
And we shared some pix of Greenway art.
And a long discussion of diamonds extracted from wiki.

And now? Now gotta go.

Che vuoi? Le pocketbook?

See you soon.

Love

Dom