Jewelry for every occasion.

Robert Lance Jewelers Philadelphia Diamond Education.

Learn about Diamonds and what exactly you are buying. We give the education in person to anyone who buys a diamond from us, we want you to ask questions and learn about what you are buying. We are very honest with all of our customers and try to make their Engagements perfect!

Diamond Shapes, not to be confused with cuts.

Diamond Shapes, not to be confused with cuts.

Buying the perfect diamond

We provide all of our customers with an education in person as to exactly what they are buying, how to identify their stones and what they are getting for the price. The first thing to consider when buying a ring is the shape of the stone, not to be confused with the cut. The shape of the stone is the first thing you visually see and everyone has their own preferences. 

This online guide is a basic breakdown of what you need to know to educate yourself before you buy. We will go over all this information in person to anyone who buys a ring from us. We are not here to confuse you into a bigger purchase, we will show you the differences and let you decide.

The Four C's

The Gemological Institute of America (GIA) made the system for grading diamonds in the1940's and it is what we will use to explain diamonds to you. The system consists of the four C's; Cut, Color, Clarity & Carat weight.

diamond cut.jpg


The cut is a scale that ranges from Excellent to Poor and this is what gives a polished Diamond it's beauty. There are 3 factors with different cuts and the closer to excellent the more beautiful the diamond will be. The three things effected by the cut are 'Brightness', 'Fire' & 'Scintillation'. The brightness of a Diamond is the combination of all white light reflecting from the surface and interior. The 'Fire' of a Diamond describes the flares of color emitted and the 'Scintillation' describes the pattern of light and dark areas, along with the sparkle. 





The second most important aspect of buying a diamond is the color. Most people think of diamonds as colorless but truly colorless diamonds are actually very rare. The scale used to identify the colors starts at D for 'colorless' and goes all the way down to Z for 'light'. One way to imagine this is D-F being spring water, G-J being tap water, K-M being puddle water and so on and so forth.

This scale also continues past Z for colored diamonds such as Fancy Yellow Diamonds. The scale for those goes from Fancy Light, Fancy Yellow, Intense, Deep & Vivid. 



The Clarity scale includes eleven clarity grades ranging from Flawless to I3. The closer to Flawless the better quality of shine and higher the price. As you go down the scale the categories are separated by inclusions. An inclusion in a diamond is a mark or blemish that can be seen under magnification, these can also be used to identify your stone. The categories VVS1 to SI2 will require a jewelers loupe to see any inclusions, once you go into I1, I2 or I3 it means the inclusions can be seen with the naked eye. There are ways to set diamonds so prongs cover inclusions, the most important thing is keeping to a price range that is comfortable.


Carat Weight

One carat equals 200 milligrams in weight. For diamonds that weigh under a carat they are divided into 100 points, similar to pennies in a dollar. Using this .75ct is 75 points and 1/2 ct. is 50 points. The obvious aspect to the 4 C's is the better quality and heavier the stone, the more expensive.