Coffin Raw Salt & Pepper Diamond (Herkimer Diamond) Engagement Ring in Black Ruthenium

Ruthenium is a platinum-group metal — the same family as platinum, palladium and rhodium — and one of the rarest elements in the earth’s crust. It is extremely hard but also brittle, which is why it is used as a finish rather than a solid metal: here it is electroplated over a solid 925 sterling silver base and tuned toward a smoky, near-black tone.

Despite the name it is not a flat jet black. It reads deep charcoal in daylight and near-black in low light, which is what makes stones and carved detail feel dimensional. Our full guide, What Is Black Ruthenium?, covers the science — or browse the whole black ruthenium collection.

Honestly: it is durable, but it is not permanent — no plated finish is. Ruthenium is one of the harder platings available and resists corrosion well, but it wears gradually at high-friction points, most often the inside of the shank, where brighter silver can begin to show through. Friction, moisture and skin chemistry decide how quickly.

That is expected rather than a fault, and many people like the lived-in, antique-blackened character it develops. The finish can also be professionally stripped and re-plated, because the sterling silver structure underneath stays intact. If you want a dark ring whose color barely changes, our black tungsten and titanium bands are coated rather than plated and hold their tone harder than any plating.

For most people, yes. Ruthenium is a platinum-group metal and is nickel-free, chemically stable and corrosion-resistant, so it rarely reacts with skin.

Because any plating is thin, the metal underneath matters too — if a finish wears through, skin can contact the base. Here that base is 925 sterling silver, which is itself nickel-free, so both the surface and the metal beneath are skin-friendly. Our Precious Metal Guide compares the options if you are highly nickel-sensitive.

They are platinum-group cousins, both electroplated, so the differences are real but subtle. Ruthenium is generally the harder of the two, so on a ring worn daily it tends to hold up marginally longer at the contact points. Black rhodium reads a touch cooler and closer to true black, and it is the more expensive metal.

If you want the deepest possible black, rhodium has a slight edge on color. If you want hardness and value, ruthenium is hard to beat. Our materials guide sets the two side by side.

Measure at home with our Ring Size Chart, or use the Find my ring size link beside the Add to Cart button. If you are between sizes, size up.

If the fit is not right when it arrives, size exchanges are free — send it back within 14 days unworn and in original condition and we will send the correct size out. No fee, no forms. Engraved rings are the one exception, as each is cut specifically for you. Full terms are on our Returns & Refunds page, and every ring is covered by our warranty against manufacturing defects.

Warm water, a drop of mild soap and a soft cloth; dry it thoroughly before it goes away. Put it on last — after perfume, lotion and hairspray — and take it off before swimming, showering, exercising, gardening or cleaning.

Skip abrasive polishes and silver dips. Those are made for untreated silver and will grind through a thin plated layer rather than clean it, and ultrasonic and steam cleaners can lift a plated surface for the same reason. Store each piece dry, in a pouch or lined box, away from harder stones. Our Jewelry Care Guide has the full routine.

These rings are kept in stock and leave our workshop in 1–4 business days; engraved orders sit at the longer end while each one is laser-cut. The estimated delivery date shown above is calculated for your order, and US shipping is free and fully insured, in a gift-ready ring box. Full timings are on our Shipping & Delivery page.

On most designs, yes — where engraving is available, a text field appears with the options above. Standard laser engraving is complimentary: up to 16 characters on women’s rings and 25 on men’s, set in Arial, with a selection of symbols included at no extra cost. Custom fonts and symbols are $25 and are arranged before you order.

See the Engraving page for examples. Engraved rings are final sale, so check your wording carefully — we engrave exactly what is entered.