A grade in GIA’s Color Grading System…. at the beginning of the “Light Yellow” category.
First introduced in 1970, on the Rolex Quartz, these synthetic crystals are now used in most watches, due to the fact that they are highly scratch resistant.
Saturation is one of three characteristics used to describe the appearance of color. Saturation (also known as intensity) refers to the brightness or vividness of a color. See also hue and tone.
These are rough diamonds that can be divided by sawing.
A person who has the job of sawing diamonds.
The horizontal cutting wheel on which a diamond is polished… also spelled scaive or scaif.
The flashes of light reflected off of the facets of a diamond when the diamond or the eye of the viewer moves. This is the bling factor! The number, the size, and the quality of the polish of the facets are all factors in the scintillation.
A fine white line, curved or straight on the surface of a diamond. A scratch would be considered during the clarity grading process. A scratch can be polished away.
See also Automatic Winding.
A jewelry setting that has the side stones already mounted, but which contains an empty set of prongs which are intended to mount a diamond center stone.
Traditionally, the four precious gemstones are diamond, ruby, sapphire and emerald. Semi-precious gemstones include everything else. But other gems have also been labelled precious at times, including opal, amethyst and pearl. Today, the distinction between precious and semi-precious gems has been rejected by some gem trade associations. See also Precious gemstones.
An identification number of a watch, usually engraved between the lugs, and/or inside/outside the case back. This number can often be used to date the production of the watch.
How a diamond is held into a piece of jewelry. For example… bead set, pave set, channel set, prong set, etc.
A metal holder for the diamond.
This effect resembles luster, and is caused by light reflection from inclusions or texture inside the gem. Luster is light reflected from the surface of the gem and sheen is reflection from inside the gemstone.
A system where the jewels on the balance staff are spring mounted, thereby protecting the balance staff from damage, in the event that the watch is dropped.
Side stones are set around or beside the center stone in a jewelry setting.
A round diamond with only 17 or 18 facets, instead of the normal 57 or 58 facets of a full cut diamond.
Most gemstones are doubly refractive — they have 2 refractive indices. Only a few gemstones have a single refractive index, specifically diamond, spinel and garnet. See also Birefringence.
Also known as a ‘clear back’ model. It features a transparent front or back, thus permitting a view of the internal workings of the watch.
Skeleton Hands (or Skellete)
Term used by Rolex to describe the hands on a watch that are ‘cut-out’ so they only feature an outline of the hands. Some of these hands are nicknamed Mercedes-style.
The surface of an unpolished diamond.
Slightly Included (SI1 and SI2)
Contain noticeable inclusions which are easy (SI1) or very easy (SI2) to see under 10X. In some SIs, inclusions can be seen with the unaided eye.
A solitaire, often found in rings and pendants, is a single stone in a simple setting. Compare Center Stone and Side Stone.
The person who separates rough diamonds into sizes and grades of quality by shape, color, and clarity.
The term used to designate a family of gemstones. For example, corundum is a species that contains the varieties sapphire and ruby. The Quartz family contains amethyst, citrine, and chalcedony, to name a few.
The study and exploration of caves. It was for these ‘cave dwellers’ (or speleologists) that the Rolex Explorer II was designed, whereby one could distinguish day from night with the use of a special 24-hour hand and bezel.
A diamond with a large table.
A small spring-loaded pushpin, which passes through the end piece into either side of the lugs, thus holding the bracelet onto the case.
The eight triangular facets around the table of a diamond that make it star-shaped.
Broad, flat facets that resemble stair steps. Emerald Cut or Asscher Cut Diamonds are cut in this style.
Subsidiary Seconds (or Sunk Seconds)
The small seconds dial, usually positioned at the 6 o’clock and is sunken so as not to impede the hour and minute hand.
Balance wheel design for the Auto Rotor Perpetual movement, patented by Rolex in 1935.
Superlative Chronometer Officially Certified
Starting in 1957, Rolex introduced this wording to replace ‘Officially Certified Chronometer’ on the dials of their chronometer-rated models, and it is still used to this day.
An area of crystal growth irregularity that does not polish the same direction as the surrounding area. Much the same as grain in wood.
Also known as the ‘step’ or ‘action.’ Sweep refers to the movement of the second hand quickly ‘ticking’ at approximately 58 times per second, thus giving the illusion of sweeping.
A gem cut consisting of thirty-three facets.
The misalignment of facets or facets that fail to point correctly to the girdle. Symmetry is regarded as an indicator of the quality of the Diamond Cutter’s care and skill in fashioning the diamond. It is graded as either Ideal, Excellent, Very Good, Good, Fair or Poor.
A synthetic gemstone is man-made rather than mined from the earth. Natural gemstones which are treated by industry-accepted methods such as heat or irradiation are not classified as synthetic.