Article · 10 min
Why the 4 Cs of diamonds matter: what each grade really changes
Why the 4 Cs of diamonds exist You keep hearing about the 4 Cs, but can you actually see the difference between grades? Not…
The Ralph Jacobs journal
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Plain-English guides to how jewellery is made, chosen and cared for. Start with a subject, or browse the latest articles below.
Article · 9 min
Why light performance matters: diamond cut explained
Why cut is said to matter most of the 4 Cs Have you been told that cut is the most important of the 4…
Article · 9 min
Why diamond carat weight and visible size don’t always match
Why same-weight diamonds can look different sizes You might compare two 1.00 ct diamonds and find that one looks clearly bigger. That matters, because…
Article · 9 min
Why does a diamond sparkle? Brilliance, fire and scintillation
Why a diamond’s sparkle needs three words: brilliance, fire and scintillation Why would a jeweller use three different words for one sparkle? Because a…
Article · 12 min
Why a GIA report matters: how to read a GIA diamond report
Why it helps to know how to read a GIA diamond report You have been handed a GIA report, full of grades, numbers and…
Article · 10 min
Why CVD vs HPHT diamonds is a growth label, not a quality grade
Why the letters CVD and HPHT matter to you You are comparing laboratory-grown diamonds, and every listing seems to say CVD or HPHT. It…
Article · 13 min
Why natural vs laboratory-grown diamonds differ: a clear comparison
Why natural vs laboratory-grown diamonds are closer than you think Choosing between a natural and a laboratory-grown diamond can feel like picking a side.…
Article · 10 min
Why the lab matters: GIA vs IGI diamond certificates
Why the lab behind a diamond grade matters You have found two diamonds that look alike on paper. One has a GIA report and…