Gemstone Guide
The art of
the colored stone
Every colored gemstone in our collection is hand-selected to AA or AAA standard — sourced from the world's finest origins, treated only where tradition demands it, and chosen for the kind of color that stops you in your tracks.
Our standard
How we grade
our gemstones
Unlike diamonds, which follow a universal 4C grading system, colored gemstones are evaluated holistically — with color as the dominant factor. We use a proprietary AA to AAA tier system to communicate quality clearly and honestly.
Color
Clarity
Origin
| Sapphire | Ruby | Emerald | |
|---|---|---|---|
| Our grade range | AA – AAA | AA – AAA | AA – AAA |
| Ideal color | Vivid royal or cornflower blue | Deep vivid red ("pigeon blood") | Pure vivid green, well-saturated |
| Treatment | Heat only | Heat only | Natural oils only |
| Origins | Kanchanaburi, Africa, Australia, Sri Lanka | Burma, Vietnam, Madagascar | Colombia, Zambia, Brazil |
| Inclusions | Eye-clean to near eye-clean | Eye-clean; fine silk acceptable | Jardin expected; a mark of natural origin |
| Hardness (Mohs) | 9 | 9 | 7.5 – 8 |
Sapphire
Corundum — Mohs 9
Prized for centuries for its celestial blue, sapphire is one of the hardest and most durable gemstones in the world. Its color ranges from pale sky to deep royal blue — the finest stones carrying a saturated, vivid tone with no grey or brown undertones.
Color is everything with sapphires. A stone can be entirely eye-clean yet fall short if its blue lacks richness. We select for depth and vividness above all else.
- Kanchanaburi, Thailand
- Africa
- Australia
- Sri Lanka
Color spectrum
Quality tiers we carry
Vivid royal or cornflower blue
Excellent saturation, eye-clean or near eye-clean, minimal visible inclusions. Color is pure and unmuddied — no grey or brown cast. Often sourced from Sri Lanka's celebrated Ratnapura deposits or Kanchanaburi's alluvial fields.
Rich, deep blue with strong color
Minor inclusions may be visible under close inspection but do not affect the stone's beauty face-up. Color is rich and saturated. Sourced from Kanchanaburi, Africa, Australia, and Sri Lanka.
Our treatment practice
Heat treatment — industry standard
Over 90% of fine sapphires worldwide are heat-treated. We follow this standard: controlled heating improves color and clarity, is universally accepted by GIA and all major gem labs, and is always disclosed. It does not diminish value.
No glass filling or beryllium diffusion
These treatments introduce foreign elements to alter color or mask structural flaws. We never use them. Every sapphire we sell has been treated only with heat — nothing more.
Sapphire is exceptionally durable at Mohs 9 — second only to diamond. It's safe for ultrasonic cleaners and steam cleaning, and resistant to everyday wear and scratching. Suitable for rings, bracelets, and any piece worn daily.
Ruby
Corundum — Mohs 9
Ruby shares its mineral structure with sapphire — both are corundum — but its chromium content gives it an unmatched depth of red, and often a vivid red fluorescence that makes the stone appear to glow from within.
The finest rubies in the world come from Burma. We also source from Vietnam and Madagascar — each origin producing distinct color signatures, from the cool purplish-red of Vietnamese stones to the warm orangy-red of Malagasy rubies.
- Burma (Myanmar)
- Vietnam
- Madagascar
Color spectrum
Quality tiers we carry
Deep vivid red — approaching pigeon blood
Strong red-to-red fluorescence, eye-clean or near eye-clean clarity. Pure red hue with no brown or orange modifier strong enough to reduce the grade. Burmese rubies at this standard are among the world's most coveted gemstones.
Rich red to slightly purplish-red
Good saturation and color depth. Minor inclusions are acceptable — fine "silk" inclusions in rubies scatter light internally and can enhance a stone's visual warmth. Sourced from Burma, Vietnam, and Madagascar.
Our treatment practice
Standard practice for fine rubies worldwide. Heat treatment reduces cloudiness, dissolves silk inclusions where desired, and intensifies color. Always disclosed, universally accepted, and does not negatively affect value when properly reported.
A known issue in the lower end of the ruby market — heavy glass filling can make a heavily included stone appear acceptable and degrade over time. We never use it. Our rubies are treated with heat only.
Ruby shares sapphire's Mohs 9 hardness and is equally durable for everyday wear. Avoid ultrasonic cleaners for heat-treated stones — warm soapy water and a soft brush are safest. Keep away from harsh chemicals and prolonged direct sunlight.
Both are corundum. The distinction is purely one of color intensity — once red saturation reaches a certain threshold, the stone earns the designation "ruby." Lighter stones straddle the line, and graders occasionally disagree. Neither is more or less genuine than the other.
Emerald
Beryl — Mohs 7.5–8
Emerald's green comes from trace amounts of chromium and vanadium — the same elements responsible for ruby's red. Its lush, saturated green has made it one of the three "precious" colored stones alongside ruby and sapphire for millennia.
Unlike sapphire and ruby, inclusions in emeralds are not only accepted but expected — the French word "jardin" (garden) describes the internal landscape of a natural emerald, and a stone with none at all would raise immediate questions about its origin.
- Colombia
- Zambia
- Brazil
Color spectrum
Quality tiers we carry
Vivid, pure green with excellent transparency
Strong, even saturation with excellent color depth. Some natural inclusions may be present — a hallmark of a genuinely natural stone, and something we seek out with great care. Often sourced from Colombia's legendary Muzo and Chivor mines.
Rich green with good transparency
Inclusions are visible but not distracting — strong, vivid color more than compensates at this level. Sourced from Colombia, Zambia, and Brazil, each origin contributing its own distinct green character.
Our treatment practice
Our emeralds arrive already beautiful — we source them that way. After cutting, we apply just a touch of natural oil to let the stone's own color and depth fully come through. That's it. No filling, no altering, no masking. The stone you see is the stone as nature made it.
Synthetic fillers like Opticon and heavy polymer treatments can mask a stone's true quality. We never use them. Our emeralds are treated only with what nature provides.
At Mohs 7.5–8, emerald is softer and more sensitive. Avoid ultrasonic and steam cleaners — the oils that enhance its beauty can be stripped by harsh chemicals or heat. Clean only with lukewarm water and a soft brush. Avoid storing loose with harder stones that could scratch it.
The internal garden of an emerald is its fingerprint — no two are alike, and experienced collectors often prize a stone's particular jardin as part of its identity. When we say inclusions are "expected," we don't mean they detract. We mean they confirm the stone is real, natural, and irreplaceable.
Shopping guide
How to read
a gemstone listing
Every gemstone listing on Jewelry Direct includes standardized quality information. Here's what each field means and why it matters.
AAA or AA
e.g. 1.25 ct
Heat / Natural oil
e.g. Sri Lanka
e.g. Oval, Cushion
14K / 18K gold
Every stone tells
a different story
Browse our full gemstone jewelry collection — each piece built around a stone chosen for the quality of its color, the integrity of its treatment, and the rarity of its origin.