The 4 C’s Buyers Guide: How To Shop For Loose Diamonds

best cut diamond - 1 carat diamond ring - best custom engagement rings

When shopping for diamonds and rings you need to know about the 4 C’s buyer’s guide in order to understand how diamonds are priced.

Learn about the 1 carat diamond price vs 1 carat diamond cost.

The 4 C’s consist of:

  • Cut- one of the most important of the 4 C’s because it directly influences a diamond’s sparkle and fire.
  • Color- an important factor, and refers to the diamond’s lack of color. A chemically pure diamond has no hue, and consequently has a higher value.
  • Carat- this is the diamond’s total weight, not necessarily size. Two diamonds with an equal carat weight differ in price based on the three other C’s.
  • Clarity- evaluation is based on the presence, or lack of internal and external carbon blemishes.
  • Shape- This is not one of the 4 C’s but is very important to the style of the diamond.

The following shopping tool interfaces from Blue Nile and Leibish organize their diamond inventory for customer browsing by the 4 C’s, shape and other characteristics.

Diamond shopping has never been so fun and precise with 360°20-40xHD views compared to the 10X views you get at traditional jewelry stores that charge you 30%-70% more for overhead costs.

Click the image below to shop for loose diamonds based on the 4 C’s grading system @ Blue Nile.

1 carat diamond ring - best custom engagement rings

Click the image below to shop for loose diamonds based on the 4 C’s grading system @ Leibish.

Leibish 4 C's Buyer's Guide Diamond Shopping Tool

1. Cut

Cut is a very important “C” because it directly influences a diamond’s sparkle. Perfect symmetry and precise cuts give diamonds the highest values. This is because a good cut yield the best sparkle that everyone is looking for.

2. Color

Color is also a very important buying factor. Color rating refers to a diamond’s lack of color. A chemically pure and structurally perfect diamond has no hue. Consequently, low hue equals high value. Moreover, the more clear the diamond is, the more value it has.  (***4 C’s color grading does not refer to fancy color diamonds. ie. blue, pink, yellow, black, etc…***)

3. Carat

Carat refers to the diamond’s total weight, not size. For example, two diamonds of equal carat weight differ in price because of the three other C’s.  A 1 carat diamond is equal to 0.2 grams. And a 5 carat diamond is equal to 1.0 grams.

1 carat diamond ring
Carat Refers To The Diamond Weight

4. Clarity 

Clarity evaluation is based on internal and external blemishes. The blemishes are microscopic. As a result, clarity is not as influential as say cut or carat.


Shape is not one of the 4C’s, but it a very crucial aspect of diamond shopping. For example, there is round shape, princess shape, cushion shape, emerald shape, pear shape, oval shape, radiant shape, Asscher shape, heart shape and marquis shape cut diamonds. But, the extraordinary sparkle of ideal cut diamonds by James Allen is available in round and princess shape cuts. 

Diamond Shapes for a 1 carat diamond ring
Diamond Shapes

The Best Custom Engagement Ring Characteristics

Superior Cut (see image above)

Cutting a diamond is a crucial step in creating a diamond with extraordinary sparkle. James Allen sacrifices the majority of the rough because it yields the best cut results. As a result one 2 carat diamond is more rare and is worth more than 2 carats of smaller diamonds. Moreover, large whole diamonds have more value than a bunch of small diamonds. 

Every diamond from James Allen ranks excellent by the GIA. The GIA assesses the angles, symmetry, and proportions. In fact, only a small percentage of diamonds qualify as a James Allen diamond. As a result, they have “good cuts” as the lowest standard and have “Astor cuts” as the highest standard. Learn more about the perfectly cut diamonds here.

Great Proportions – 

The proportions of a diamond affect the how it reacts to light. Diamonds cut out of proportion restricts the light it reflects. Consequently, James Allen carries diamonds with has ideal cut proportions. As a result, their diamonds have maximum sparkle, fire, and beauty.


Wonderful Symmetry – 

custom engagement rings

The anatomy of a diamond describes the different parts the cuts (see diagram). Furthermore, precise symmetry ensures each anatomical part of the diamond aligns perfectly. James Allen takes time on symmetry. Consequently, their diamonds reflect the maximum amount of light for their price. 

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1 Carat Diamond Ring
The 4 C's Buyer's Guide | How to Shop For Loose Diamonds
1 Carat Diamond Ring Shopping In 360°20xHD & 5 Vital Tips To Smart Buying
The 4 C's Buyer's Guide | How to Shop For Loose Diamonds
Shop securely for the best 1 carat diamond ring online. Walk-in jewelry stores have epic overhead costs, consequently you save 30%-70% online. Use the right tools: 360°View in 20x-40xHD. And The Diamond Search Filter Tool. | 922 Ring Settings: ($240 - $8,310) | 81,381 loose .90ct.-1.99ct. diamonds: ($1,120 - $72,690)|.
When you want to build the best custom engagement rings, you need to know about the 4 C's diamond grading standards. The 4 C's buyer's guide is the GIA bench-marking system for buying loose diamonds. The 4 C's consist of cut, color, carat, clarity and shape.
John Diamond
1 Carat Diamond Ring Shopping Tips
1 Carat Diamond Ring Shopping Tips

John Diamond

Hi. My name is John Diamond. This world is changing fast and one of those big changes is how people are buying engagement rings online vs traditional jewelry stores. That is why I am here to educate you how to buy high quality custom engagement rings and give specific 1 carat diamond ring shopping to save 30%-70% on the highest quality diamond rings.