This is what Meghan Markle's engagement ring will look like

Things between Prince Harry and Meghan Markle are getting serious.

And, if rumours are to be believed, it’s only a matter of time before the couple gets engaged.

The 32-year-old Prince and Suits actress have been dating for almost a year now and are increasingly appearing in public together.

He even took her as his date to Pippa Middleton’s wedding last month which, royal or not, is a big deal.

So, as rumours of their engagement continue, there is mounting speculation about what kind of engagement ring the young royal is likely to choose.

Harry has a number of impressive jewels at his disposal — including his mother’s jewellery collection and other engagement royal engagement rings, as well as something new from one of Meghan’s favourite designers.

Perhaps most likely, he would look to his mother’s jewellery, left to him and his brother William when she died.

In her will, Princess Diana reportedly wrote: ‘I would like you to allocate all my jewellery to the hare to be held by my sons, so that their wives may, in due course, have it or use it.’

The obvious choice would have been Diana’s engagement ring, however William gave this to Kate Middleton when he proposed to her in 2010.

Diana's engagement ring — consisting of 14 solitaire diamonds and a 12-carat oval blue Ceylon sapphire set in 18-carat gold — was originally given to Harry. But the brothers reportedly had a pact that whoever married first would get the engagement ring.

Their mother famously wore sapphire in other pieces of jewellery as well, including earrings, necklaces and bracelets. So, it would be no great surprise if Harry decided to lean towards this sentimental stone for his to-be bride.

If that were the case, he could choose one of the two engagement rings given to the Queen mother by King George VI. One of these was a large sapphire set in Welsh gold, which she later repurposed with a pearl surrounded by diamonds.

These rings were reportedly returned to the royal vaults on her death.

However, there is a chance this would be too similar to the Duchess of Cambridge's ring, in which case he might be inclined to choose something different.

Diana also wore many pieces of emerald jewellery, including one necklace given to her by the Queen as a wedding present, which she famously wore as a headband.

Some royal watchers have suggested Harry might choose one of the emeralds from this particular necklace to get set into a custom-made ring, surrounded by diamonds.

This would also be following in the steps of his grandfather — Prince Philip designed a square-cut ring with diamonds from a tiara of his mother’s for the Queen.

Harry might also choose a ring of Princess Margaret’s (also stored in the royal vaults), which had a ruby stone surrounded by diamonds in the shape of a rosebud.

Lorna Haddon, buyer at Beaverbrooks the Jewellers, told the Daily Express the most likely option would be for Harry to take a coloured gem from one of Diana’s necklaces and surround it with diamonds.

She added Harry was likely to go with some unique to reflect Meghan’s “unique fashion sense and style”.

But for now, we join the rest of the world in keeping an eye on Meghan's left ring finger for the a sparkler worthy of a princess.