The 4 C's of Diamonds

Diamond Guide

The purchase of a diamond is a significant investment, so we're very pleased that more and more of our clients are learning to make informed purchases when it comes to buying a diamond. Even if you don't buy a diamond from us, our trained associates are here to help; feel free to drop by anytime and ask someone to guide you through what you need to know before buying a diamond. If you'd like to do some pre-reading before you start looking, have a peek at the guide below.

We want to warn you though, no image and no detailed description can begin to describe the beauty of a diamond as seeing one in your own hand will. That's where we can help.

The Essential 4 Cs

The 4 Cs of diamond quality are the best place to start when learning about diamonds. They represent the industry standard for decades in quantitatively measuring the quality of a diamond.

Cut

In diamond grading, the "cut" usually refers to the quality of the cut, not the shape. The measurements range from Poor to Excellent. When light enters a diamond, it reflects off the inside faces of the diamond, "bouncing" around inside, and then returning to your eye, sometimes with a beautiful rainbow of refraction, like a prism. For over 100 years, diamond cutters have analyzed the angles of a diamond to determine how to return the most light to your eye. A diamond with an Excellent cut will sparkle like a Poor cut diamond never could. The value of a diamond with good proportions, symmetry and polish is significant and often underestimated.

The cut of a diamond influences several of its properties. Brightness is a measure of the white light that reflects from the diamond, back to your eye. Fire is the spectrum of colours that you catch fleeting glimpses of when moving a diamond in the light. It's describes how a diamond can acts like a "prism" splitting white light into all of the colours of the rainbow. Scintillation describes the brightest flashes of light that occur when a diamond is moved in the light. It's how a nice diamond can catch your eye from across the room.

Colour

A perfect diamond is a pure lattice of carbon atoms with no imperfections. Part of the natural allure of diamond is that they aren't perfect, but some imperfections, such as accumulations of nitrogren atoms in the lattice, result in lower quality diamonds with less than perfect colour. With some fancy coloured diamonds excepted, the more colourless a diamond is, the greater its value. Most diamonds you will see in a jewellery store are "colourless" (D, E, or F colour) or "near-colourless" (G, H, or I colour). Near-colourless stones begin to show some hints of yellow or brown when examined closely.

Diamond Colour Scale Examples
Gemological Institute of America, Inc.

The scale for diamond colour is based on the alphabet, and ranges from D (no colour) to Z (deep colour). The slight change from one letter grade to the next is often impossible to detect with an untrained eye, but one step in the scale can drastically change the price of a diamond.

Clarity

The scale for a diamond's clarity ranges from FL (flawless) to I3, with the I standing for "included". Inclusions in a diamond occur for a wide variety of reasons and are related to how the diamond was formed. Inclusions are actually one of the major factors that allow jewellers to identify genuine natural diamonds and diamond simulants.

Some inclusions are cloudy, some are white and some are black. More than just the quantity and size of inclusions is important when grading a diamond. Grades also have to look at the colour, location, and several other factors, to determine the degree to which inclusions negatively affect the diamond's properties.

Flawless diamonds are extremely rare and have no visible inclusions or blemishes, even under 10× magnification. VVS1 to VVS2 diamonds are very very slightly included, VS1 to VS2 are very slightly included, S1 ad S2 are slightly included and I1 to 13 diamonds are moderately to heavily included. In the I range, the poor clarity begins to interfere with the transparency and light transmittance of a diamond.

Diamond Clarity Diagram
Gemological Institute of America, Inc.

Carat

Carat weight is the "C" that most of you already know. It denotes the size of the diamond. A one (1) carat diamond weighs 200 milligrams. Carats may also be measured as 100 points, like a dollar can be measured as 100 pennies. That's means that a half (0.50) carat diamond is equivalent to a 30 point diamond.

Most jewellery-grade diamonds are not a full carat and are often described as a fraction of a carat, like a third-of-a-carat engagement ring has approximately a 0.33 ct diamond.

Carat Diagram

For jewellery pieces that have many diamonds, the carat weight may be measured and recorded as the sum of the weight of all the diamonds. For example a 1.00 ct total weight diamond ring may have one large centre stone, or it may have three 0.33 ct stones. It is also worth noting that a 1.00 ct diamond warrants greater value, and a higher price, then would two 0.50 ct diamonds.

Images and information courtesy of the Gemological Institute of America.

Contact Us

  • 227 Main Street East,
    Milton, ON L9T 1N9
  • 905-875-2999
  • This email address is being protected from spambots. You need JavaScript enabled to view it.

Hours

Mon-Wed: 9:00am - 6:00pm
Thurs - Fri: 9:00am - 8pm
Sat: 9:00am - 5:00pm
Sun: Closed