{"product_id":"herkimer-diamond-coffin-cut-ring","title":"Coffin Raw Salt \u0026 Pepper Diamond (Herkimer Diamond) Engagement Ring in Black Ruthenium","description":"\u003cstyle\u003e .product-rich-content { font-family: inherit; color: #2a2a2a; line-height: 1.65; max-width: 720px; margin: 0 auto; } .product-rich-content h2 { font-size: 1.35em; font-weight: 600; color: #1a1a1a; margin-top: 2em; margin-bottom: 0.5em; padding-bottom: 0.4em; border-bottom: 1px solid #dcdcdc; letter-spacing: -0.01em; } .product-rich-content h2:first-child { margin-top: 0; } .product-rich-content p { margin: 0.8em 0; } .product-rich-content ul { padding-left: 1.4em; margin: 0.8em 0; } .product-rich-content li { margin-bottom: 0.4em; } .product-rich-content a { color: #4a4a4a; text-decoration: underline; } .product-rich-content .lead-paragraph { font-size: 1.05em; color: #1a1a1a; padding: 1em 1.2em; background: #f2f2f2; border-left: 3px solid #4a4a4a; border-radius: 4px; margin-bottom: 1.5em; } .product-rich-content .feature-pills { display: flex; flex-wrap: wrap; gap: 0.5em; margin: 1.2em 0; } .product-rich-content .feature-pills .pill { background: #f2f2f2; color: #4a4a4a; padding: 0.4em 0.9em; border-radius: 100px; font-size: 0.88em; font-weight: 500; border: 1px solid #dcdcdc; } .product-rich-content .ring-callout { display: grid; grid-template-columns: 1fr 1fr; gap: 1em; margin: 1.2em 0; } .product-rich-content .ring-callout .ring-card { padding: 1em 1.2em; background: #fafafa; border: 1px solid #ececec; border-radius: 6px; } .product-rich-content .ring-callout .ring-card h3 { font-size: 0.95em; font-weight: 600; margin: 0 0 0.4em 0; color: #4a4a4a; letter-spacing: 0.04em; text-transform: uppercase; } .product-rich-content .ring-callout .ring-card p { margin: 0.4em 0; font-size: 0.92em; } .product-rich-content .spec-card { background: #fafafa; border: 1px solid #ececec; border-radius: 6px; padding: 1.2em 1.5em; margin: 1em 0; } .product-rich-content .spec-card ul { margin: 0; } .product-rich-content .spec-card li { list-style: none; padding: 0.35em 0; border-bottom: 1px dashed #e8e8e8; } .product-rich-content .spec-card li:last-child { border-bottom: none; } .product-rich-content .spec-card strong { display: inline-block; min-width: 140px; color: #1a1a1a; } .product-rich-content .product-faq { margin-top: 2.5em; } .product-rich-content .product-faq h2 { margin-bottom: 1em; } .product-rich-content .faq-item { border: 1px solid #e8e8e8; border-radius: 6px; margin-bottom: 0.6em; background: #fff; transition: border-color 0.2s ease; } .product-rich-content .faq-item:hover { border-color: #4a4a4a; } .product-rich-content .faq-item summary { cursor: pointer; padding: 0.9em 1.1em; font-weight: 500; list-style: none; color: #1a1a1a; position: relative; padding-right: 2.5em; } .product-rich-content .faq-item summary::-webkit-details-marker { display: none; } .product-rich-content .faq-item summary::after { content: \"+\"; position: absolute; right: 1.1em; top: 50%; transform: translateY(-50%); font-size: 1.3em; color: #4a4a4a; font-weight: 300; transition: transform 0.2s ease; } .product-rich-content .faq-item[open] summary::after { content: \"−\"; } .product-rich-content .faq-item[open] summary { border-bottom: 1px solid #dcdcdc; } .product-rich-content .faq-item p { padding: 0 1.2em 1em; margin: 0.6em 0 0; color: #4a4a4a; } @media (max-width: 600px) { .product-rich-content .ring-callout { grid-template-columns: 1fr; } .product-rich-content .spec-card strong { display: block; min-width: auto; margin-bottom: 0.2em; } } \u003c\/style\u003e \u003cdiv class=\"product-rich-content\"\u003e \u003cp class=\"lead-paragraph\"\u003eStart with the honest part: a Herkimer diamond is not a diamond. It is a natural, doubly terminated quartz crystal, and this one is raw enough to show the smoky mineral clouds inside it — the same speckled depths that make a salt and pepper diamond ring so magnetic. Cut to a coffin silhouette, framed by simulated diamonds, and set against a black ruthenium finish over solid 925 sterling silver, it turns that moody, galactic look into something genuinely wearable.\u003c\/p\u003e \u003cdiv class=\"feature-pills\"\u003e \u003cspan class=\"pill\"\u003eNatural Herkimer Quartz\u003c\/span\u003e \u003cspan class=\"pill\"\u003eCoffin Cut, 7 x 10 mm\u003c\/span\u003e \u003cspan class=\"pill\"\u003eApprox. 2.1 ct\u003c\/span\u003e \u003cspan class=\"pill\"\u003eSalt \u0026amp; Pepper Look\u003c\/span\u003e \u003cspan class=\"pill\"\u003eBlack Ruthenium Finish\u003c\/span\u003e \u003cspan class=\"pill\"\u003eOne-of-a-Kind Stone\u003c\/span\u003e \u003c\/div\u003e \u003ch2\u003eWhat a Herkimer Diamond Actually Is\u003c\/h2\u003e \u003cp\u003eThe name is a nickname, not a classification. Herkimer diamonds are quartz crystals that grow with two naturally pointed ends and a glassy, already-faceted clarity, which is what earned them the comparison in the first place. They are not carbon, they are not graded on the diamond scale, and no honest listing should imply otherwise. What they are is roughly 7.5 on the Mohs scale, entirely natural, and completely individual. Our full explainer covers \u003ca href=\"\/blogs\/journal\/what-is-a-herkimer-diamond-origin-meaning-value-complete-guide\"\u003ewhat a Herkimer diamond is\u003c\/a\u003e, and \u003ca href=\"\/blogs\/journal\/herkimer-diamond-rings-are-they-durable\"\u003ehow durable Herkimer rings really are\u003c\/a\u003e answers the practical question.\u003c\/p\u003e \u003ch2\u003eThe Salt and Pepper Look, Without the Diamond Price\u003c\/h2\u003e \u003cp\u003eSalt and pepper diamonds are prized for the black and white inclusions suspended inside them — storm clouds, static, a galaxy caught mid-collapse. A raw Herkimer crystal grows its own version of that weather, and this stone is black and white through the body for exactly that reason. If you love the aesthetic but not the price of a genuine included diamond, this is the closest natural stand-in there is, and it does not require pretending it is something it is not. We compare them directly in \u003ca href=\"\/blogs\/journal\/herkimer-diamond-vs-salt-and-pepper-diamond-which-is-right-for-your-ring\"\u003eHerkimer diamond vs salt and pepper diamond\u003c\/a\u003e, and \u003ca href=\"\/blogs\/journal\/what-is-a-salt-and-pepper-diamond\"\u003ewhat a salt and pepper diamond is\u003c\/a\u003e explains the original.\u003c\/p\u003e \u003ch2\u003eCoffin Cut, Art Deco Frame\u003c\/h2\u003e \u003cp\u003eThe coffin cut is an elongated hexagon with a flat top and tapered shoulders — architectural, a little gothic, and unmistakably deliberate. At 7.0 x 10.0 mm and around 2.1 ct it commands the finger without needing a halo to bulk it out. The setting takes its geometry from Art Deco jewelry: hard lines, symmetry, and simulated diamond accents placed to sharpen the outline rather than soften it. See the shape family in our \u003ca href=\"\/collections\/coffin-cut-engagement-rings\"\u003ecoffin cut engagement rings\u003c\/a\u003e, or the whole stone family in \u003ca href=\"\/collections\/herkimer-diamond-engagement-rings\"\u003eHerkimer diamond engagement rings\u003c\/a\u003e.\u003c\/p\u003e \u003ch2\u003eThe Black Ruthenium Finish\u003c\/h2\u003e \u003cp\u003eUnderneath is solid 925 sterling silver. Over it sits black ruthenium, and the effect is the reason this ring works: a dark, gunmetal band drains all the brightness out of the metal, so the only light in the piece comes from the crystal and its accents. Against a polished silver band the stone's smoky inclusions would compete with the shine; against black they read as depth.\u003c\/p\u003e \u003cp\u003eRuthenium is a platinum-group metal, the same family as rhodium and platinum, and it is the harder of the two common black finishes — which is why we use it rather than black rhodium. It plates as a genuinely dark gunmetal rather than a tinted gray, and it holds that color under daily wear. Explore more of the look in our \u003ca href=\"\/collections\/black-finish-rings-bold-modern-distinct\"\u003eblack finish rings\u003c\/a\u003e and \u003ca href=\"\/collections\/black-rings\"\u003eblack rings\u003c\/a\u003e collections, or read about the styling in \u003ca href=\"\/blogs\/journal\/black-rings-for-women-meaning-styles-and-how-to-choose\"\u003eblack rings for women\u003c\/a\u003e.\u003c\/p\u003e \u003ch2\u003eNo Two Are the Same\u003c\/h2\u003e \u003cp\u003eBecause every Herkimer crystal forms with its own pattern of inclusions and its own balance of black to white, the stone you receive will not match the photographs exactly — it will be close in cut and size and entirely its own in character. Some arrive nearly clear with a few dark threads, others are dense with mineral cloud. That variation is not a flaw in the product; it is the product. If you want a stone that looks identical to a catalog image, this is not the ring for you.\u003c\/p\u003e \u003ch2\u003eSpecifications\u003c\/h2\u003e \u003cdiv class=\"spec-card\"\u003e \u003cul\u003e \u003cli\u003e \u003cstrong\u003eCenter stone\u003c\/strong\u003e Natural Herkimer diamond (quartz crystal)\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eStone creation\u003c\/strong\u003e Natural, raw\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eShape \/ cut\u003c\/strong\u003e Coffin\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eStone size\u003c\/strong\u003e 7.0 x 10.0 mm\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eCarat weight\u003c\/strong\u003e Approx. 2.1 ct\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eColor\u003c\/strong\u003e Black and white\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eAccent stones\u003c\/strong\u003e Simulated diamonds (CZ)\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eBase metal\u003c\/strong\u003e Solid 925 sterling silver\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eFinish\u003c\/strong\u003e Black ruthenium\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eIncludes\u003c\/strong\u003e Luxury velvet jewelry box, free U.S. shipping\u003c\/li\u003e \u003c\/ul\u003e \u003c\/div\u003e \u003ch2\u003eSizing \u0026amp; Care\u003c\/h2\u003e \u003cp\u003eThe ring is made in the size you select, so measure with our \u003ca href=\"\/pages\/find-your-size\"\u003ering size guide\u003c\/a\u003e before ordering. For care, wipe the ring with a soft, dry cloth after wearing and clean the stone with mild soap, warm water, and a soft brush when it needs it. Skip ultrasonic and steam cleaners entirely — a raw crystal with natural inclusions does not respond well to either. Keep the ring away from chlorine and abrasive polishes, which wear any dark finish. Store it dry in its box, away from harder stones, and take it off for gardening, gym sessions, and heavy lifting.\u003c\/p\u003e \u003cdiv class=\"product-faq\"\u003e \u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eIs a Herkimer diamond a real diamond?\u003c\/summary\u003e\u003cp\u003eNo. A Herkimer diamond is a natural quartz crystal, not carbon, and it is not graded on the diamond scale. It earned the nickname from its glassy clarity and naturally pointed, already-faceted shape.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWhy does it look like a salt and pepper diamond?\u003c\/summary\u003e\u003cp\u003eRaw Herkimer crystals grow with black and white mineral inclusions suspended inside them, which produces the same smoky, speckled depths people love in salt and pepper diamonds. This stone is black and white through the body for that reason.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eIs the center stone natural?\u003c\/summary\u003e\u003cp\u003eYes. It is a natural, raw Herkimer quartz crystal. Nothing about its internal pattern is manufactured, which is why every stone differs.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWill my stone look exactly like the photos?\u003c\/summary\u003e\u003cp\u003eNo, and that is intentional. Cut and size match, but the pattern of inclusions is unique to each crystal. Some arrive nearly clear with a few dark threads, others are dense with mineral cloud.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eHow large is the stone?\u003c\/summary\u003e\u003cp\u003eIt measures 7.0 x 10.0 mm and averages approximately 2.1 ct. The elongated coffin outline covers a good stretch of the finger without needing a halo.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWhat is a coffin cut?\u003c\/summary\u003e\u003cp\u003eAn elongated hexagon with a flat top and tapered shoulders. It is an architectural, slightly gothic shape that suits raw and included stones better than a round brilliant does.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWhat is the black finish on the band?\u003c\/summary\u003e\u003cp\u003eSolid 925 sterling silver plated in black ruthenium, which gives the metal a dark gunmetal tone. Draining the brightness from the band is what lets the crystal's smoky depths read as depth rather than competing with a polished shine.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWhat is black ruthenium?\u003c\/summary\u003e\u003cp\u003eRuthenium is a platinum-group metal, the same family as rhodium and platinum. As a black finish it is harder and holds its color better than black rhodium, and it plates a genuinely dark gunmetal rather than a tinted gray.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWill the black finish wear off?\u003c\/summary\u003e\u003cp\u003eNot with normal wear. Ruthenium is hard and bonds well to sterling silver. Like any plated finish it can thin after years of daily contact — keep it away from chlorine and abrasive polishes, and we can refinish the ring if it ever needs it.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eAre the accent stones diamonds?\u003c\/summary\u003e\u003cp\u003eNo. They are simulated diamonds, also called cubic zirconia, placed to sharpen the Art Deco outline of the setting.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eIs quartz durable enough for an engagement ring?\u003c\/summary\u003e\u003cp\u003eAt around 7.5 on the Mohs scale, Herkimer quartz is well suited to daily wear with sensible care. It is softer than sapphire or moissanite, so remove the ring for rough work and store it away from harder stones.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eHow should I clean it?\u003c\/summary\u003e\u003cp\u003eUse mild soap, warm water, and a soft brush, then pat dry. Avoid ultrasonic and steam cleaners completely, since a raw crystal with natural inclusions does not respond well to either.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eCan I wear it every day?\u003c\/summary\u003e\u003cp\u003eYes, with the usual habits. Take it off for gardening, the gym, and heavy lifting, store it dry in its box, and it will hold up to regular wear.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWho is this ring for?\u003c\/summary\u003e\u003cp\u003ePeople who want a genuinely unusual engagement or statement ring, who like dark and gothic-leaning jewelry, and who would rather have a one-of-a-kind natural crystal than a stone that looks like everyone else's.\u003c\/p\u003e\u003c\/details\u003e \u003cdetails class=\"faq-item\"\u003e\u003csummary\u003eWhat comes with my order?\u003c\/summary\u003e\u003cp\u003eThe ring arrives in a luxury velvet jewelry box with free U.S. shipping. Our gemstones are conflict-free and selected for ethically responsible origins.\u003c\/p\u003e\u003c\/details\u003e \u003c\/div\u003e \u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Is a Herkimer diamond a real diamond?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. A Herkimer diamond is a natural quartz crystal, not carbon, and it is not graded on the diamond scale. It earned the nickname from its glassy clarity and naturally pointed, already-faceted shape.\"}},{\"@type\":\"Question\",\"name\":\"Why does it look like a salt and pepper diamond?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Raw Herkimer crystals grow with black and white mineral inclusions suspended inside them, which produces the same smoky, speckled depths people love in salt and pepper diamonds.\"}},{\"@type\":\"Question\",\"name\":\"Is the center stone natural?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. It is a natural, raw Herkimer quartz crystal. Nothing about its internal pattern is manufactured, which is why every stone differs.\"}},{\"@type\":\"Question\",\"name\":\"Will my stone look exactly like the photos?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No, and that is intentional. 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