Cushion Cut Lab Grown Diamond Three Stone Engagement Ring with Half Moon Side Stones in Silver, 10K, 14K and 18K Gold

A cushion cut laboratory grown diamond with a half moon diamond set hard against each side, flat edge to the centre stone and curved edge outwards. The three stones touch, so there is no metal showing between them and the cluster reads as one continuous band of diamond across the finger. The shank is squared off and completely plain.

At a glance

• Centre stone: Cushion cut laboratory grown diamond
• Carat options: 2, 3, 4 and 5 carat
• Colour and clarity: E colour, VVS2 clarity
• Certificate: IGI, included free
• Setting: Claw set cushion with a half moon cut diamond on each side
• Accent stones: Half moon cut laboratory grown diamonds, E colour, VVS2
• Metals: 925 silver, 10K, 14K and 18K gold in yellow, rose and white
• Made: To order in Surat, India

Half moon side stones

A half moon, sometimes called a demi lune, is exactly what it sounds like, a stone with one straight edge and one curved one. Set with the straight edge facing inwards it meets the flank of the cushion with no gap at all, which is something no round or pear can do. The curved outer edge then softens the ends of the cluster so the ring has no hard stop.

Why it looks wider than its carat weight

Because the three stones sit edge to edge rather than spaced along the shank, they form a single uninterrupted surface. There is no metal breaking the line, so the eye reads the whole width as one large diamond rather than three separate ones. It is the most efficient way we know to make a three stone ring look big.

A cut that has to be made to order

Half moons are cut to fit a specific centre stone. The straight edge has to match the exact width of that individual cushion, and the depth has to be right so the tables all sit level. This is why the design is made around your stone rather than assembled from parts.

What laboratory grown means here

A laboratory grown diamond is a diamond. It is crystallised carbon with the same cubic structure, the same 10 on the Mohs scale, the same refractive index of 2.42 and the same dispersion as a mined stone. Ours are grown by chemical vapour deposition and high pressure high temperature methods, then cut and polished by hand. This is not moissanite, not cubic zirconia and not a simulant. A gemmologist testing it will read diamond, because it is diamond.

Metals

Choose 925 sterling silver, or 10K, 14K or 18K gold in yellow, rose or white. White gold is photographed here and is the usual choice, because a colourless metal against three E colour stones keeps the whole surface reading white. 10K is the hardest alloy, 14K is the everyday balance, and 18K is the richest colour but the softest metal. White gold is rhodium plated and will want replating every one to two years.

Every centre stone arrives IGI certified

The centre diamond is graded by IGI, the International Gemological Institute, and the certificate comes with the ring at no extra charge. It states the carat weight, the E colour grade, the VVS2 clarity grade, the measurements and the girdle inscription, and confirms in writing that the stone is laboratory grown.

Made to order in our own workshop

Mapple Gems is a family run workshop in Surat, India, where most of the world's diamonds are cut and polished. Setting three stones edge to edge with no visible metal between them is the hardest part of this ring, and it is done by hand under a microscope. Allow two to three weeks for making, plus shipping.

Looking after it

Warm water, mild washing up liquid and a soft toothbrush. The seams where the half moons meet the cushion are tight, so work the brush along them properly. Take it off for the gym, gardening and swimming.

Questions we are asked

What colour and clarity is the diamond? Every centre stone is E colour and VVS2 clarity, on every metal and every carat weight. The half moon side stones are matched to the same grade.

Do the side stones grow with the carat option? Yes. They are cut in proportion to the centre, so a 5 carat cushion carries visibly larger half moons than a 2 carat one.

Is the certificate really free? Yes. The IGI report for the centre stone is included in the price on every variant.

Will a wedding band sit flush against it? Yes. The half moons step down to the shank, so a straight band meets the ring cleanly on both sides.

Can it be resized? Yes. All three stones sit in the head and none are set in the shank.

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