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When buying diamonds, as with any major purchase, the more you know, the better you can protect yourself from misrepresentation and fraud. With that in mind, Marks Jewelers is providing you with everything you need to know about buying diamonds.

At first, an independent diamond grading report or certificate and an insurance replacement appraisal may seem like a similar document. However, they are vastly different and it is very important to understand the differences between the two when purchasing a diamond.


An independent diamond grading report or certificate is an independent quality report about a specific diamond. It is issued by a diamond grading laboratory with no affiliation to any retailer, giving the consumer a completely objective opinion on the diamond’s quality. This document includes the exact measurements, proportions, color grade, clarity grade, cut grade and carat weight of the diamond. It also includes specifics that most jewelers do not have the equipment or knowledge to determine such as the diamond's fluorescence, polish and symmetry*. Each document is numbered, dated and illustrates the internal and external characteristics of the diamond, otherwise known as a 'plot'.


The purpose of an insurance replacement appraisal is to establish the average retail replacement value in most common and appropriate markets for the function of establishing a baseline for obtaining insurance coverage and determining insurance premiums. An insurance appraisal is requested by an owner who wishes to obtain insurance on a given item. The retail replacement value represents the cost to replace the described item with a comparable item, as near as possible, to the original, in the retail jewelry market or other markets appropriate to the item described. When available, independent diamond grading reports or certificates may be quoted in insurance replacement appraisals and can be used to assist with determining current and future replacement values.


The leading diamond laboratories in the world are the Gemological Institute of America (G.I.A.), The Forevermark Diamond Institute and the European Gemological Laboratory (E.G.L.). Any diamond can be evaluated by G.I.A or E.G.L. for a fee. The Forevermark Diamond Institute tracks the diamond’s source and therefore will not accept diamonds from outside it’s own supply chain. It is important to mention that the G.I.A and Forevermark standards are stricter than the E.G.L.

GIA (The Gemological Institute of America) - established in 1931 and is recognized as the world’s foremost authority in diamond grading. The G.I.A. grades natural, synthetic and treated diamonds. G.I.A. refers to their document as a Diamond Grading Report or a Diamond Dossier (depending on carat weight).

Forevermark Diamonds are graded at the Forevermark Diamond Institute in Antwerp, Belgium. As a De Beers group of companies, the Forevermark Diamond Institute uses cutting-edge technology and grading processes, as well as 125 years of diamond expertise, to carefully inspect every diamond, going beyond the technical qualities to hand-pick only those diamonds that are truly beautiful. The Forevermark Diamond Institute will only grade natural and untreated diamonds. Forevermark diamonds are sourced from mines that not only comply with their strict political, financial, social and environmental requirements, but also benefit the communities in which they are operating. The Forevermark Diamond Institute refers to their document as a Diamond Grading Report.

EGL USA's (European Gemological Laboratory) main office opened in 1977 in the diamond district in New York and has established a reputation of fast turnaround time and fair grading standards and grades natural, synthetic and treated diamonds. E.G.L. refers to their report as a Certificate.

EGL International - founded in Belgium in 1974 and has a presence in most diamond exchanges throughout the world. EGL International is known to be more lenient in their diamond grading. It is not uncommon to see a difference of 2-4 color grades and 1-2 clarity grades when comparing to the GIA or Forevermark. E.G.L. International refers to their report as a Certificate.

In terms of actual grading (color and clarity) the GIA and Forevermark are stricter than the EGL. There are also other labs that certify diamonds and their grading standards may vary.

*Marks Jewelers is equipped with a long and short wave ultraviolet light box as well as a Sarin machine to determine the diamond’s fluorescence, polish and symmetry.

Click here to view our customer awareness guide that informs you more about the facets of jewelry.

Please call us with any questions that may not be answered here: 1(215) 362-7132.

Click here to find out more about how to buy the perfect Diamond Engagement Ring.


A diamond's life began as crystallized carbon millions of years ago and more than 100 miles beneath the Earth’s surface. It then endured a violent journey upwards through the Earth’s crust, surviving immense pressures and temperatures, until it was deposited at the Earth’s surface. When that diamond deposit was detected, miners excavated and crushed 1 ton of ore to extract less than half a carat of rough diamond.That is less than the weight of a large paper clip!

Once they are mined, cut, and polished, diamonds are customarily graded. The Gemological Institute of America (GIA) has created the International Diamond Grading System which is used by jewelry professionals around the world to determine the quality of a stone. Four grading categories are used to describe and classify diamonds: clarity, color, cut, and carat weight - more commonly known as the Four Cs. The higher the grade in each of the categories - the rarer the stone.


In its purest state, a diamond is composed of carbon atoms and is colorless, like the De Beers Millennium Star. When certain impurity atoms replace carbon atoms, they impart tints of color. Yellow diamonds and most blue ones result from nitrogen and boron, respectively, trapped in the diamond’s structure. Diamonds that are pink to red and orange in color have imperfections at the atomic level which scientists call “color centers.” Green, blue-green, and a small number of blue diamonds are a special case. Their colors result from exposure to radiation over millions of years in the Earth. In all of these cases, portions of white light striking the diamond are absorbed. The remaining portions of light that are not absorbed are transmitted to the eye and result in the color we see.


A diamond may be the hardest substance known to man, but to keep it looking its best, it needs proper care and maintenance. This is especially important if you wear your diamond every day. To keep daily build-ups of soap, cosmetics, and skin oils from dulling your beautiful jewelry, follow any one of the following procedures to care for your gem:

Professional Cleaning

This is the best option and also gives you the opportunity to have your retail jeweler check your diamond’s mounting to make sure prongs or other settings are not weak or loose. At Marks Jewelers, our professional team of experts will clean, polish, and check your diamonds for FREE. We assure the best possible job and take care of our customers’ jewelry as if it was our own.

Cold Water Soak

A mixture of half cold water and household ammonia will work well if your ring or diamond jewelry is allowed to soak for 30 minutes. Lift your ring out and clean gently around the front and back of the mounting with a small, soft brush. Give the ring a second swish through the solution and let dry on a paper towel. No rinsing is necessary.

Over-the-Counter Jewelry Cleaners

Ask your jeweler for a liquid jewelry cleaner made especially for diamonds and follow the instructions on the label. A good cleaner is designed to remove loose dirt and dissolve any oils or residue on the stone.

Detergent Bath

The simplest cleaning method for your diamond is to soak your jewelry in a small bowl of warm, sudsy water combined with any mild liquid detergent. Use a toothbrush or other soft brush and gently brush the ring around the setting while it is in the water. After its bath, put the ring in a fine wire strainer and rinse thoroughly under warm running water (the strainer provides protection for the ring from slipping down the drain). Pat your ring dry with a soft lint-free cloth.

Ultrasonic Cleaning

The simplest cleaning method for your diamond is to soak your jewelry in a small bowl of warm, sudsy water combined with any mild liquid detergent. Use a toothbrush or other soft brush and gently brush the ring around the setting while it is in the water. After its bath, put the ring in a fine wire strainer and rinse thoroughly under warm running water (the strainer provides protection for the ring from slipping down the drain). Pat your ring dry with a soft lint-free cloth.

This method involves a special machine that uses a high-frequency vibration to clean the ring. The ring is enclosed in a small cup with cleaning solution and in just a minute, any dirt and oils are removed from the stone. The method can be done by your jeweler or at home after purchasing an ultrasonic cleaner.

  • July 3rd, 2019 By Dennis

    “Unbelievable, hassle free experience. From texting back and forth with Josh on a Saturday on the VIP event and the engagement ring options, to receiving and email from Dave that night with options for me to review to Tuesday going in and going in and purchasing while having a beer while I waited. Outstanding experience. Well done!”

  • June 26th, 2019 By John

    “I have been a customer of Marks jewelers for over 30 years. Over this time I have purchased many items from custom rings to bracelets. You cannot match the quality of the product that Jim sells This is now a family tradition. Both my son in laws and my son buy from Marks. Will go nowhere else for quality fine jewelry.”

  • June 19th, 2019 By Daniel

    “My experience at Marks Jewelers was wonderful. They created me a custom necklace that captured everything I could have possibly hoped for. The designers and Beth helped me work through my thoughts to create a piece that has deep meaning. Beth was amazing to work with and was patient with all my ideas. Thank you Beth and the team of designers.”

  • June 5th, 2019 By Jaki

    “The Marks in Montgomeryville is the only jewelry store that I trust with all my jewelry repairs and purchases. I make the 40 min drive every time because I know I'm going to get incredible service from anyone there and great prices.”

  • June 4th, 2019 By Amy

    “I can’t rave enough about my experience with Marks Jewelers. Olivia spent hours with me to design a couple pieces of jewelry with stones I had and Jacqueline created a couple of molds perfecting it. The end result is better than I ever imagined. My experience was so personalized and professional. Quality and a great price!!”

  • May 6th, 2019 By Lauren

    “My fiancé got my ring from there last August and it’s today my Dad and I went to turn my mom's wedding ring into my band and Jim was so helpful made me feel so comfortable and showed me exactly what the final product will look like! I’m so excited to receive my one of a kind wedding band! Marks is truly the best jeweler around!”

  • April 10th, 2019 By Ed

    “I needed a 3-tier tier pearl necklace restrung and I brought it to Mark's Jewelers. Although it is costume jewelry, it has much sentimental value to my wife. I wasn't sure if they would work on costume jewelry oh, but they did! They did a fantastic job! The drop-off and pick-up experience was terrific! Everyone was so professional. I highly recommend this place! I will be back!”

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