Skip to main contentSkip to footer
  • Visit One of Our 5 Locations!Toggle Visit One of Our 5 Locations! Menu
    • Swansea, IL
    • Waterloo, IL
    • Effingham, IL
    • Alton, IL
    • Ballwin, MO
  • Give Us a Call!Toggle Give Us a Call! Menu
    • Swansea, IL
    • Waterloo, IL
    • Effingham, IL
    • Alton, IL
    • Ballwin, MO
Reiniger Jewelers logo
  • Shop All
    Shop by Category
    Engagement RingsWedding BandsEarringsNecklaces & PendantsRingsBraceletsChildren's JewelryMen's JewelryCharms
    Classic Styles
    Diamond StudsTennis BraceletsSolitaire NecklacesGemstone Jewelry
    Diamond Jewelry
    EarringsNecklaces & PendantsRingsBraceletsLab Grown Diamonds
    Lab Diamond Jewelry
    EarringsNecklaces & PendantsRingsBracelets
    Gemstone Jewelry
    Birthstone JewelryEarringsNecklaces & PendantsRingsBracelets
    Fashion Jewelry
    EarringsNecklaces & PendantsRingsBracelets
    Watches
    Bulova WatchesSeiko WatchesObaku WatchesMen's WatchesWomen's Watchs
    Menu image
  • Bridal
    Engagement Rings
    Complete RingsLab Grown RingsRing SettingsDesign Models
    Wedding Bands
    Eternity BandsWomen's BandsMen's BandsSilicon Bands
    Custom Bridal Jewelry
    Start from ScratchGabriel & Co. BridalEngagement Ring BuilderWedding Band Builder
    Loose Dimaonds
    Education
    The 4Cs of DiamondsChoosing the Right Setting
    Menu image
    Menu image
  • Diamonds
    Loose Diamond by Shape
    RoundPrincessEmeraldOvalCushionRadiantPearHeartMarquiseAsscherView All
    Diamond Jewelry
    EarringsNecklaces & PendantsRingsBracelets
    Lab Diamond Jewelry
    EarringsNecklaces & PendantsRingsBracelets
    The 4Cs of Diamonds
    Menu image
    Menu image
  • Designers
    Allison Kaufman
    Ania Haie
    Bulova
    Dee Berkley
    EFFY
    ELLE
    Frederic Duclos
    Gabriel & Co.
    Heavy Stone Rings
    Imperial Pearls
    INOX
    Obaku
    Rembrandt Charms
    Seiko
    Menu image
  • Custom
    Learn Our Process
    Our Portfolio
    Engagement Ring Builder
    Wedding Band Builder
    Make an Appointment
    Menu image
    Menu image
  • Services
    Cleaning & Inspection
    Custom Jewelry
    Payment Options
    Gold & Diamond Buying
    Jewelry Appraisals
    Jewelry Education
    Jewelry Engraving
    Jewelry Insurance
    Jewelry Repairs
    Pearl & Bead Restringing
    Rhodium Plating
    Ring Resizing
    Tip & Prong Repair
    Watch Battery Replacement
    Watch Repairs
    Menu image
  • About Reiniger
    About Us
    Our Reviews
    Social Media
    Menu image
    Menu image
  • Visit One of Our 5 Locations!Toggle Visit One of Our 5 Locations! Menu
    • Swansea, IL
    • Waterloo, IL
    • Effingham, IL
    • Alton, IL
    • Ballwin, MO
  • Give Us a Call!Toggle Give Us a Call! Menu
    • Swansea, IL
    • Waterloo, IL
    • Effingham, IL
    • Alton, IL
    • Ballwin, MO
Reiniger Jewelers logo
Log In My Cart
  • Toggle Search Menu
  • Toggle My Account Menu
    Login
    Forgot Password?

    Don’t have an account? Sign up now

  • Toggle My Wishlist
  • Toggle Shopping Cart Menu
  1. Home
  2. Education
  3. Diamonds

Learn About Diamonds

The Four Cs of Diamonds:
Our Four C's of Diamonds guide can help you decide on the most important factors when shopping for a diamond. The Four C's of diamonds are known as Carat Weight, Cut, Color and Clarity.

Diamond Carat Weight

The word carat derives from the word carob, a Mediterranean seed, which has an extremely consistent weight for measuring. The greater the carat weight, the rarer, and more valuable the diamond becomes. Five metric carats weighs exactly 1 gram.

Some people want the largest diamond possible. If size is a priority, we at Reiniger Jewelers can help you classify the proper cut, color and clarity to fit your budget economically, and fit your jewelry beautifully. Many of our engagement rings can fit diamonds up to five carats or more, but each ring has different size constraints based on its size and the type of setting. Prong settings can be manipulated to fit virtually any size diamond, but tension-set diamonds and bezel set diamonds have more limitations on size.

  • Dime for size comparison
    17.9 MM
  • Search for a Round diamond, 0.10 carat (3.0mm diameter)
    0.10 CT
    (3.0 MM)
  • Search for a Round diamond, 0.15 carat (3.4mm diameter)
    0.15 CT
    (3.4 MM)
  • Search for a Round diamond, 0.20 carat (3.8mm diameter)
    0.20 CT
    (3.8 MM)
  • Search for a Round diamond, 0.25 carat (4.1mm diameter)
    0.25 CT
    (4.1 MM)
  • Search for a Round diamond, 0.5 carat (5.1mm diameter)
    0.5 CT
    (5.1 MM)
  • Search for a Round diamond, 0.75 carat (5.8mm diameter)
    0.75 CT
    (5.8 MM)
  • Search for a Round diamond, 1 carat (6.4mm diameter)
    1.0 CT
    (6.4 MM)
  • Search for a Round diamond, 1.25 carat (6.9mm diameter)
    1.25 CT
    (6.9 MM)
  • Search for a Round diamond, 1.5 carat (7.4mm diameter)
    1.5 CT
    (7.4 MM)
  • Search for a Round diamond, 1.75 carat (7.8mm diameter)
    1.75 CT
    (7.8 MM)
  • Search for a Round diamond, 2 carat (8.1mm diameter)
    2.0 CT
    (8.1 MM)
  • Search for a Round diamond, 2.5 carat (8.8mm diameter)
    2.5 CT
    (8.8 MM)
  • Search for a Round diamond, 3 carat (9.4mm diameter)
    3.0 CT
    (9.4 MM)
  • Search for a Round diamond, 3.5 carat (9.8mm diameter)
    3.5 CT
    (9.8 MM)
  • Search for a Round diamond, 4 carat (10.2mm diameter)
    4.0 CT
    (10.2 MM)
  • Search for a Round diamond, 5 carat (11.0mm diameter)
    5.0 CT
    (11.0 MM)
  • Round diamond, 6 carat (11.8mm diameter)
    6.0 CT
    (11.8 MM)
  • Round diamond, 7 carat (12.4mm diameter)
    7.0 CT
    (12.4 MM)
  • Round diamond, 8 carat (13.0mm diameter)
    8.0 CT
    (13.0 MM)
  • Round diamond, 9 carat (13.5mm diameter)
    9.0 CT
    (13.5 MM)
  • Round diamond, 10 carat (14.0mm diameter)
    10.0 CT
    (14.0 MM)
  • Round diamond, 12.5 carat (14.5mm diameter)
    12.5 CT
    (14.5 MM)
  • Round diamond, 15 carat (16.0mm diameter)
    15.0 CT
    (16.0 MM)

Diamond Cut

The true definition of cut is the quality of the proportions and symmetry of the diamond. Your diamond's proportions make a vast difference on how brightly your diamond shines. An 'ideal cut' diamond is one that allows the maximum amount of light to return through the top of the diamond, which takes into consideration the depth, table size, crown height and angle, girdle thickness and more. Our diamond professionals will be happy to assist you in selecting the best diamond cut.

After a rough diamond is mined, it is evaluated to determine its best possible cut, in order to maintain the maximum clarity, color, and carat weight. The term 'cut' is often confused with diamond 'shape', such as round brilliant or princess cut.

Diamond anatomy

Ideal

This is the rarest cut grade and reflects the most light.

Excellent

This cut grade reflects a high level of craftsmanship and light performance.

Very Good

This cut grade reflects nearly as much light as an Excellent cut grade, but for a lower price.

Good

This cut grade reflects most of the light that enters the diamond, but not as much as a Very Good cut grade.

Fair

This cut grade may appear dull or even glassy, and is very inexpensive.

Poor

This cut grade is not carried by Reiniger Jewelers and is typically not recommended.

Diamond Color

Color is one of the more noticeable attributes of a diamond and has a heavy impact on the price of the stone. Diamonds range from colorless to yellow or light brown, and are sometimes found in a spectrum of fancy colors, including yellow, blue, and even red diamonds. The less color, the rarer the diamond. After 'Z' on the color scale, diamonds become fancy yellow, which cost more because of their rarity.

F
E
D
F color diamond
E color diamond
D color diamond

Colorless

J
I
H
G
J color diamond
I color diamond
H color diamond
G color diamond

Near Colorless

Z-N
M-K
L color diamond
K color diamond

Noticeable Color

Z-N
M-K
J
I
H
G
F
E
D
L color diamond
K color diamond
J color diamond
I color diamond
H color diamond
G color diamond
F color diamond
E color diamond
D color diamond

Noticeable Color

Near Colorless

Colorless

Diamond Clarity

Diamonds are composed of mostly carbon. During the heating process, other elements become trapped inside, giving each diamond its own unique fingerprint. These inclusions help identify the clarity of your diamond. All diamonds are viewed through a 10x magnification lens by diamond graders.

Close up of inclusions in a diamond

(F) Flawless

No inclusions or blemishes are visible to a skilled grader.

(IF) Internally Flawless

No inclusions and only blemishes are visible to a skilled grader.

(VVS1-2) Very Very Slightly Included

Inclusions are difficult for a skilled grader to see.

(VS1-2) Very Slightly Included

Inclusions are clearly visible but can be characterized as minor.

(SI1-3) Slightly Included

Inclusions are noticeable to a skilled grader.

(I1-3) Included

Inclusions are obvious and may affect transparency and brilliance.

Shop Loose Diamonds
Five Convienent Locations!
Swansea Location
2704 North Illinois Street
Swansea, IL 62226
(618) 235-1219
Store Information
Waterloo Location
871 N. Illinois Route 3
Waterloo, IL 62298
(618) 939-4367
Store Information
Effingham Location
1304 Thelma Keller Ave
Suite 102
Effingham, IL 62401
(217) 803-8903
Store Information
Alton Location
317A Homer M Adams Parkway
Alton, IL 62002
(618) 465-1410
Store Information
Ballwin Location
14442 Clayton Road
Ballwin, MO 63011
(636) 557-7020
Store Information
Our Store Hours
Mon-Fri:Monday - Friday:
10:00am - 5:00pm
Saturday:
10:00am - 3:00pm
Sunday:
Closed
Store Menu
  • About Us
  • Careers
  • Payment Options
  • Our Reviews
Our Jewelry
  • Engagement Rings
  • Wedding Bands
  • Earrings
  • Necklaces and Pendants
  • Rings
  • Bracelets
  • Estate Jewelry
  • Children's Jewelry
  • Men's Jewelry
  • Charms
  • Watches
Our Collections
  • Allison Kaufman
  • Ania Haie
  • Bulova
  • Dee Berkley
  • EFFY
  • ELLE
  • Frederic Duclos
  • Gabriel & Co.
  • Heavy Stone Rings
  • Imperial Pearls
  • INOX
  • Obaku
  • Rembrandt Charms
  • Seiko
Become a Member

Join for free and discover exclusive access to our biggest drops, promotions, members-only products, and more.

Join Now for Free
Follow Us
  • Visit the gia website
  • Visit the authorizenet website
  • Visit the rjo website
  • Visit the synchrony website
  • Return Policy
  • Privacy Policy
  • Terms & Conditions
  • Accessibility Statement

© 2026 Reiniger Jewelers. All Rights Reserved.

Powered by: Punchmark

My Bag
Shopping cart contents
Loading

Learn how we use cookies in our Privacy Policy or manage cookie preferences.