Buying Black Diamond Stud Earrings

Everything you need to know!

black diamond stud earringsWhether you're shopping for a gift or for yourself, deciding from the huge array of stud earrings for sale can be a little bit daunting! Here are a few tips to help you make a smart decision.

The 4 C's (Minus Two)

You probably are familiar with (or at least have heard of) the "four c's" - color, clarity, cut and carat weight - which jewelers use for evaluating diamonds.

Regardless of whether they are natural or enhanced, very little light passes through black diamonds. This means that for practical purposes, color and clarity take a bit of a "back seat" to the other "c's" - cut and carat weight.

Some tips on color and clarity:

- Most retail jewelry features diamonds which are (in descending order of quality) Very Slightly included (VS1, VS2), Slightly Included (SI1, SI2), or Included (I1,I2, I3). Poorer clarity is more noticeable the larger the diamond.

- White diamonds have color grades ranging from D (colorless) through Z (light yellow. Stones in the G-J range are popular and appear colorless to the casual observer. A yellow gold setting will enhance diamonds with a lower color grade, making them appear less yellow because of the contrast.. White gold, platinum or sterling silver settings will have the opposite effect, making any hint of yellow more noticeable.

This is not to say that color and clarity aren't important. Color greatly affects the price of naturally colored diamonds, and a treated black diamond which has been poorly color-enhanced may carry a noticeable greenish cast. A diamond with poor clarity can have inclusions which make it prone to damage. That said, diamond earrings are at a much lower risk for chipping or breakage than, for example, a ring - especially tiny studs which nestle right up against your ear.

You should however check that your black diamonds have good surface finish - they should be polished to a mirror like appearance, with no obvious abrasions or chips. Surface flaws like these will mar their appearance.

Now let's take a look at cut , carat weight (and size).. and how to choose a setting.


Nearly all black diamond studs sold in retail stores and online are either brilliants (round) or princess cut (square). You may be able to get studs in other fancy shapes from a jeweler, but nearly all diamond studs sold in retail stores are in those two popular shapes.

Princess cut diamonds have smaller table (surface) dimensions than round brilliants with the same carat weight. This is because more of the stone's weight is in the pavilion (lower part of the stone), as illustrated below:

brilliant vs princess cut diamond - side view

Carat Weight and Size

Size is, at least in my opinion, one of the most difficult factors to estimate without actually seeing a piece of jewelry. Carats represent the stone's weight, but the way an individual diamond is cut can alter its dimensions.

If you are buying black diamonds to wear by themselves or in a primary piercing, I wouldn't recommend going any smaller than 1/2 or 1/3 ctw (total carat weight) for the pair. Smaller earrings would be fine for multiple piercings, for a child or if you want a very understated look. The most popular sizes are between 1/4ctw and 2 ctw, which is 1/8 carat to 1 full carat per earring.

The following chart (which works for all diamonds, not just black ones) gives the approximate size, in millimeters, per earring for the most common carat weights. As mentioned earlier, due to the way they are cut, princess cut diamonds have slightly smaller dimensions than round brilliants of the same carat weight.

Total Carat Weight (pair) Carat Weight
per earring
Size in mm each earring
Round Brilliant
brilliant cut
Size in mm each earring
Princess Cut
princess cut
1/4 carat (0.25) 1/8 carat (0.125) 3.2mm 2.6x2.6mm
1/3 carat (0.33) 1/6 carat (0.175) 3.6mm 3x3mm
1/2 carat (0.50) 1/4 carat (0.25) 4.1mm 3.4x3.4mm
3/4 carat (0.75) 3/8 carat (0.375) 4.6mm 3.9x3.9mm
1 carat (1.00) 1/2 carat (0.50) 5.2mm 4.5x4.5mm
1.5 carats (1.50) 3/4 carat (0.75) 6mm 5x5mm
2 carats (2.00) 1 carat (1.00) 6.5mm 5.5x5.5mm
3 carats (3.00) 1.5 carats (1.50) 7.4-7.5mm 6.5x6.5mm
Approximate dimensions (in millimeters) for diamond stud earrings

What is that in inches?

Millimeters: = Inches    


The type of setting used to hold the diamond also plays a part in the look and durability of your earrings.


Choices for black diamonds are generally sterling silver, white gold or yellow gold, with white gold and sterling being the most popular choices. Sterling is less expensive and softer than gold and is prone to tarnish - more so on some people than on others. White gold can cause a reaction in people who are allergic to nickel.

For black diamonds, the color of the metal is a matter of personal preference. However if you're buying white diamonds, stones with lower color grades will look whiter in a yellow gold setting, while stones with better color grades will be further enhanced by white gold.

Setting Style

The most common type of setting for diamond studs is a basket setting. Basket settings have prongs which hold the top (table) of the diamond and a ring of metal around the prongs forming a "basket" below which supports the stone's pavilion (base) while allowing light to pass through. For round diamonds, the stone is held in place by 4 (occasionally 3) equally-spaced prongs. Princess cut diamonds will have 4 prongs - one at each corner of the stone. This not only secures the diamond in the setting, but helps protect the corners from chipping.

You may also be able to find round diamond studs in a martini setting. A martini setting has longer prongs picture a martini glass. Very little metal is visible, so it looks like the stone is set right against your ear. Unlike the basket setting, there is no metal supporting the lower portion of the prongs so they are more easily bent if you catch them on something. For this reason, you may want to avoid this type of setting for costly or irreplaceable stones.

A bezel setting has metal which surrounds the table (top) of the diamond extending over the lower portion of the stone. This obscures the sparkle of a colorless or fancy-colored stone. But since black diamonds are nearly opaque to begin with, if you enjoy a sleek, modern look, a bezel setting may be something to consider. Bezel set studs earrings aren't as popular so there isn't as much of a selection, but you may occasionally be able to find a pair of bezel-set black diamond earrings online.

Earring Backs

Last but not least, let's talk about the backs which secure the earrings. Less expensive stud earrings and black diamond studs set in silver will almost always have the standard "butterfly" backs, which secure themselves to the earring post by friction. If you are buying a more expensive pair of stud earrings, you should get ones with backs that screw in place - screw backs make it almost impossible to accidentally lose an earring.

Author Mary G., AJP, is a GIA (Gemological Institute of America) alumni and an Accredited Jewelry Professional.