In preparing to cut a diamond the rough crystal is studied until the grain is found. Along the grain another sharp-pointed diamond is ground until there is a V-shape incision or nick. The blunt end of a flat piece of steel is placed in this nick and a smart blow of a hammer divides the crystal evenly and perfectly. After this

Old Square Cut Diamonds.

English Square Cut Diamonds.

"cleavage" has removed the unnecessary portions, or they have been sawed off by the use of rapidly-revolving thin wheels charged with diamond dust, the diamond is set in a turning wheel and ground with another diamond until it takes the shape in which we know it.

The fifty-eight facets are cut and polished one at a time on a rapidly-revolving wheel charged with diamond dust and oil. It takes from two and one-half to four days to properly cut a stone. Knife-edge girdle diamonds are impractical owing to the liability of chipping the thin edge in setting or by blows while being worn.

LUMPY-DIAMOND.

FISHEYE DIAMOND.

Polishing the rough edge of the girdle is rarely done and then usually to conceal a girdle which is too thick or lumpy. The principal diamond cutting centers are Amsterdam, Antwerp and New York..

Inherent flaws can be perfectly understood by imagining a pond of water frozen solidly to its center. At the shore, where the ice has been partly forced out along the banks, it will be full of grass, leaves, pebbles and sticks, and presents a broken and frosted appearance. Further out there are only traces of such debris, some bubbles, spots, etc. Out at the center is clear, transparent, unbroken, unflawed,

MOSTLY FLAWS SURROUNDED BY DIAMOND.

CULET OUT OF CENTER.

CARBON SPOT FAVORABLY SITUATED.

CARBON SPOT.

BADLY SITUATED purest blue-white ice, such as you delight to see in your glass on a hot day. So is it with diamonds; some (like the ice along the shore) are full of cracks, carbon specks, bubbles, clouds, splits and cavities; some have all of these; some only a few; others only one, and some are without flaws.

Of all the imperfections (not considering glaring cracks or nicks), carbon spots are the most discernible. They range from mere specks scarcely visible with a powerful magnifying glass, to large black spots or clusters of large or small black specks sometimes quite plain to the naked eye. These are carbon which failed to crystallize with the rest of the diamond, or intrusions of titanic iron. The blackest and often most numerous carbon specks occur in the finest white and blue-white stones. "Capes" and other yellow diamonds are usually perfect, something in the color of these stones seemingly being of a nature which helps clear and perfect crystallization. Blue-white stones of exceptionally fine color are often massed full of shaggy or jet-black carbon spots.

White specks and bubbles are common flaws, which vary in size and which may be best illustrated by looking at a pane of glass in your window. There you will find small knots, white bubbles and whitish specks. These seldom injure the brilliancy, as they are often a glittering silver color, more brilliant than the diamond.

Clouds are dark flat patches in the grain, of a brownish color, and appear as a sprinkling of dust in a small patch in the interior. This seldom injures brilliancy.

Glessen or glasses are flat sectional streaks having an icy appearance. When large or abundant they disturb or cut off the proper reflection of the interior light rays, causing an appearance known as "shivery." When clouds or glessen occur at the surface of a diamond they appear as cracks, and if at or near the girdle are dangerous, as the stone is liable to split or crack there when being mounted or by any hard blow, which would result in the loss of a sliver or wedged-shaped piece out of the edge.

WHITESPECKS BUBBLES.

CLOUDS.

GLESSEN.

Surface flaws consist of nicks or cavities in the face of the stone either above or below the girdle. The brilliancy of the diamond hides these flaws when the diamond is clean, but when clouded with soap and dust these cavities fill up and show plainly.

NICKS.

SPLINTERS

CRACK

PERFECT CUT BUT BADLY FLAWED.

CAVITY.

BARGAIN DIAMOND.

Diamonds are so brilliant, the radiance from the facets so bewildering to the eye, that the flaws cannot be seen by the human eye unless the imperfection is pronounced and at the top surface of the diamond. Each facet of a diamond (by reason of the method of cutting) is a window looking down a clearly defined walled chamber, like a hall-way to the culet. With a one-inch loup or magnifying glass such as watchmakers and diamond dealers use, it is possible to clearly look down through each facet and its hall-way to the culet, and observe throughout each chamber the very slightest imperfection if one exists, thus thoroughly examining and exploring the entire diamond.

Diamond brilliancy is of two kinds: "surface brilliancy" and "internal brilliancy." Light falling vertically on a diamond is reflected back in straight, unbroken rays. This constitutes "surface brilliancy." Light falling in a slanting direction is partly reflected and partly enters the stone; that part which enters is refracted or bent and causes the "internal brilliancy."

In a perfectly cut diamond, the facets are so carefully arranged that entering rays of light jump from wall to wall of this transparent enclosure and emerge again at the very point of entry Cleverly arranged mirrors sending a ray of light from one to all the others and back again to the first will produce the same effect. Lights entering a diamond are reflected, refracted and dispersed. The dispersion of a ray of white light separates it into its component color rays. These are the spectrum colors often seen radiating from a diamond. Placing a diamond in the sun's rays and holding a sheet of white paper at the proper angle to catch the reflections from the stone clearly shows these colors.

Brilliancy is often said to be the most important quality of a diamond, but that is not true. Yellow diamonds are more flashingly brilliant than white stones that cost much more. In each color grade, greater brilliance determines higher value over stones of the same color grade with less brilliancy. The diamond is the hardest known substance in the world, cutting and grinding all other known hard things, but itself only cut and ground by its mates.

Because of their hardness, diamonds worn by many previous generations remain as brilliant as they were in the beginning and they will continue so to the end of time. No other thing can scratch or mar the polished facets and sharp corners of the diamond. It is the hardest of all known things. While all diamonds are of practically the same hardness, this is not, however, absolutely true, as stones from wet diggings or rivers are slightly harder than those from dry diggings. All diamonds are infusible and unaffected by acids or alkali. The heat of a burning building will not affect them, they can be raked from the ashes uninjured and can only be burned in oxygen under a scientifically produced intense heat of 4000° F. While the hardest known thing, the diamond is brittle and can be crushed to a powder. It is the only absolutely pure gem, being composed of crystallized carbon - all others are composed of two or more elements

Modern American Cut Diamonds.

The term "Shibboleth" has come to mean a countersign or password of a secret society since the Biblical days, when the Ephraimites, who had been routed by Jephthah, tried to pass the Jordan. They were made to pronounce the word "Shibboleth" and were easily detected as enemies when they pronounced it "Sibboleth."