Why Moissanite Colour Matters More Than Most Sellers Admit
Moissanite is one of the most brilliant gemstones available — but it has a well-known quality variable that many sellers gloss over: colour. Buy without understanding it and you might end up with a stone that shows noticeable yellow or green tints under certain lighting conditions. Buy with this guide in hand, and you'll know exactly what to ask for.
At Heritage & Co., every stone we sell is independently GRA-certified and sourced to a strict colour standard. This guide explains why that matters and what it means for your ring.
How Moissanite Colour Grading Works
Moissanite is colour-graded on a scale adapted from the diamond industry's GIA D–Z scale. However, because moissanite is a different mineral (silicon carbide vs carbon), its colour presentation differs slightly from diamond.
The three main colour grades you'll encounter:
- D–F (Colourless): The premium tier. Appears bright white in virtually all lighting conditions. No visible warmth, no green or yellow cast. This is the standard Heritage & Co. sources exclusively.
- G–H (Near-Colourless): Slight warmth visible when compared side-by-side with colourless stones. In isolation, most people cannot detect a difference. Acceptable but not ideal for white gold settings.
- I–J and below: Noticeable warmth or tint. Can appear yellow in direct sunlight or under bright indoor lighting. Not recommended for fine jewellery.
The Green Tint Issue: What Causes It?
Moissanite's unique optical properties — including its high birefringence (double refraction) — mean that under certain light sources, particularly LED lights and fluorescent lighting, some moissanite stones can emit a subtle green or grey flash. This is distinct from the colour grade and can occur even in D-colour stones.
The green tint issue is most pronounced in:
- Older generations of moissanite (pre-2015 manufacturing)
- Very large stones (3ct+) in certain cuts
- Stones with lower colour grades (H and below)
- Certain cuts that emphasise dispersion over brilliance (some cushion cuts)
How Heritage & Co. addresses this: We source exclusively from suppliers who produce current-generation moissanite with enhanced colour processing. Our stones are tested under multiple light sources before being approved for sale. If a stone exhibits noticeable green flash at normal viewing distances, it doesn't make it into our collection.
How to Evaluate Moissanite Colour Before You Buy
If you're buying online, here's what to look for:
Check the GRA certificate: The Gemological Research Association (GRA) certificate will state the colour grade. Look for D, E, or F. Any certificate that says "colourless" without specifying the grade is not a full certificate — it's a marketing statement.
Ask for video under multiple lights: A good seller will show you the stone under warm LED, cool LED, and natural daylight. The stone should appear consistently white-to-bright across all sources. If they only show photos, ask specifically for video.
Consider the setting colour: A D-colour moissanite in a yellow gold solitaire will appear slightly warmer due to reflection from the metal — this is normal and expected. If you want the most optically white result, a white gold or platinum prong with yellow gold band is ideal.
Cut matters as much as colour: A well-cut moissanite in G-colour will outperform a poorly-cut D-colour every time. Prioritise cut quality first, then colour.
Moissanite Colour vs Diamond Colour: Are They Comparable?
Not directly. A D-colour moissanite and a D-colour diamond will both appear colourless, but they achieve that appearance through different optical mechanisms. Moissanite is more refractive (higher RI: 2.65–2.69 vs diamond's 2.42), which means it produces more rainbow fire — the coloured flashes you see as the stone moves.
Some people love this about moissanite — it's part of what makes it optically distinct from diamond. Others prefer the subtler brilliance of diamond. Neither is objectively better; it comes down to personal preference.
What matters for colour: in both cases, stones graded D–F will appear white and clean in all normal lighting conditions. This is the standard to hold any seller to.
Which Moissanite Colour Grade Should You Choose?
Our recommendation at Heritage & Co. is straightforward:
- For white gold or platinum settings: D–F only. The contrast between the cool metal and a slightly warm stone is more visible in these settings.
- For yellow gold settings: D–F is still ideal, but G–H can work well since the warm metal reflects into the stone and the slight warmth reads as harmonious rather than off-colour.
- For rose gold settings: D–F is ideal. Rose gold has enough warmth of its own — a warm stone in a rose gold setting can look unintentionally muddy.
Heritage & Co. sources D-colour moissanite as standard across all our engagement rings. This isn't the cheapest option — D-colour stones cost more to source — but it's the right standard for a ring meant to last a lifetime.
Questions to Ask Any Moissanite Seller
Before you buy from any jeweller, ask these questions directly:
- What colour grade is this moissanite, and can you show me the GRA certificate?
- Is this current-generation moissanite? What year was it manufactured?
- Can you show me video of this stone under different light sources?
- What's your returns policy if I'm not satisfied with the colour in person?
A confident, knowledgeable seller will answer all of these without hesitation. Evasive or vague answers are a red flag.
If you'd like to ask us directly, WhatsApp us at +27 82 818 9106 — we'll walk you through exactly what you're getting, in writing, before you commit to anything.
The Heritage & Co. Colour Standard
Every moissanite in our collection is:
- D–F colour grade (colourless), independently verified by GRA certification
- Current-generation manufacturing (no legacy green-tint issues)
- Tested under warm LED, cool LED, and natural light before approval
- Available for viewing via video on request before purchase
Browse our full moissanite engagement ring collection — every stone meets this standard, and the certificates come with the ring.