Jewellery VideoHow gems are graded — colour, clarity, cut, weight beyond diamonds
Coloured stones grade differently — colour leads, species context does the rest.
Coloured gems do not use the diamond 4Cs as-is — species context changes
the grading tree.
Colour (the big one) — hue, tone, saturation. A 5/5 emerald is greener
than fine; the same numbers mean different things per species. Trade
poetry ("pigeon's blood", "imperial") describes saturation tiers.
Clarity — by species expectation — emeralds are EXPECTED to include
(jardin); aquamarines are expected clean. Graders compare each stone to
its species norm, not to a universal scale.
Cut — symmetry, proportion, finish — and for coloured stones, ORIENTATION
for best face-up colour (pleochroic stones like tanzanite live or die by
this).
Weight — per-carat prices step up at size thresholds because large
clean material is exponentially rarer.
The systematic version of all this — with real stones in hand — is the
gemmology foundation course; the free webinars
demonstrate grading on camera.
Go deeper — free
Watch the free replays at the gem webinar library — the gem e-book is the written companion. When curiosity becomes commitment, the gemmology foundation course is the ladder's first rung (online entry: GT100e); dates on the calendar. Play Name That Gem to train the eye between sessions.
What students say
“I love all subjects, especially metalsmithing. I just love to fire and shape things.”
— Angie K. (Singapore) · published student feedback
“Attended the courses here and it's worth way more than what you have to pay for. The instructors are all super approachable and welcoming everytime they see you. The tools needed are provided and you get to bring home the crafts that you make during the class. Even the class schedules are pretty flexible. I enjoyed myself here a lot and will definitely sign up for more classes.”
— Nebulla L. (Singapore) · published student feedback
Free ways to explore
No sign-up, no payment — start with any of these.
Full recorded sessions — the best free starting point.JDMIS on YouTubeFREE
Course previews, blended-learning explainers and school life.Free jewellery webinar replaysFREE
Recorded sessions on design and the jewellery industry.Download the gem e-bookFREE
The school's free guide to gems — pairs with the replays.
See the online and blended options
Gemmology can be started fully online, and every classroom course at JDMIS has a video-supported path.
Visit jdmis.edu.sg