Precious Diamonds  - Quality diamonds and custom diamond jewelry
Diamond Tutorials

Our Cut, Carat, Color and Clarity tutorials show how common grading varies from AGS and GIA standards, how diamonds with above-average cut quality improve in appearance and how true "Super Ideal Cut" Diamonds break the rules - in a positive way.

Most diamonds look nice under bright lights, but become noticeably average in normal conditions. Those which continue to sparkle and dance have good cut quality. At Precious we separate cut quality into two areas; Cut Performance, which revolves around light return, and Cut Precision which can take top performing diamonds to an even higher level. Cut Performance should be a prerequisite for Cut Precision. Understanding that, diamonds which enjoy high performance and precision are dazzling and rare treasures to behold.

Our Performance Tutorial shows how to measure overall light return, brightness and contrast in diamonds. You will be introduced to the world’s only scientifically adopted system for grading cut performance, the American Gem Society ASET® and its precursor, the Ideal-Scope®.

Our Precision Tutorial shows how to determine optical symmetry (aka “Hearts & Arrows” in round diamonds) which can improve contrast, dispersion and scintillation in diamonds which already enjoy top light performance.

At Precious we focus on the top 1% of all diamond's, those with the highest cut quality, best and best proportions, resulting in the best light performance (sparkle).

We invite your questions or comments at any time, by phone or from our contact page.






HRD Diamond High Council of Europe
McDonnell Diamonds LLC
99 Pine Hill Road #648
Nashua, NH 03063 USA

011 353 1 671 0055 (IRL)
Federation of Jewellery Manufactures of Ireland

© McDonnell Diamonds LLC: Some content used with permission.