Can I resize an antique engagement ring?

Most antique bands tolerate resizing up or down a few sizes without trouble. A skilled bench jeweller cuts the shank, adds or removes a section of matching metal, and solders it closed again. Keep in mind that rings with intricate engraving all the way around the band pose a problem. Sizing these usually disrupts the pattern, so it's a trade-off.

My grandmother gave me an old ring with a dull greyish diamond in it, and I was wondering if the stone is supposed to look like that?

Older diamonds were cut by hand before the invention of modern proportions. These cuts emphasise a soft glow rather than the sharp light you see in contemporary stones. Dirt also plays a large role. Antique mounts with closed backs trap soap and oils behind the stone over decades, deadening the light return. Have a jeweller check the setting before cleaning. If the metal is secure, a gentle wash often brings the stone back to life.

How do you clean them safely?

Warm water, a drop of mild dish soap, and a soft baby toothbrush shift most dirt. Gently brush behind the setting where dust gathers. Don't soak rings with foil-backed stones or seed pearls. Water seeps behind these settings and ruins the materials.

I love the look of Edwardian rings but I have a hands-on job, so will the fine platinum settings hold up to everyday wear?

Platinum is a dense and durable metal, which is why Edwardian jewellers trusted it for such delicate pierced designs. It resists wearing thin much better than gold does over a long period. That said, the metal on century-old pieces is often thin to begin with. Heavy manual work crushes a fragile gallery or bends a slender shank out of round. Take them off before doing heavy lifting.