EXTREMELY RARE Herkimer Diamond — 11.88 carats Exceptional clarity - NO RESERVE PRICE - Height: 16.5 cm - Width: 14.4 cm- 2.38 g - (1)

Discover this exceptional natural 11.88-carat Herkimer diamond, a magnificent mineral specimen distinguished by its complex crystallization, impressive transparency, and remarkable natural architecture.

This piece features a superb, particularly well-defined pyramidal termination, accompanied by a fascinating crystal structure composed of multiple brilliant faces and natural reliefs that give it a spectacular appearance.

One of the most remarkable features of this specimen is its geometry. Its elegant, slender upper termination rises above a more complex crystal structure, whose many faces reflect light from different angles.

This combination of a well-defined termination and irregular crystalline reliefs reflects the particular conditions under which the crystal developed.

The specimen’s transparency is also remarkable. Some areas are beautifully clear, revealing its many internal structures, while others display natural inclusions, crystalline veils, and fractures that create a veritable mineral landscape.

Under suitable lighting, the different faces produce intense reflections, evoking the characteristic brilliance of the most sought-after crystals in this family.

With its substantial weight of 11.88 carats and dimensions of 16.5 × 14.4 × 8.6 mm, this piece has a particularly impressive presence for an individual specimen.

The combination of its size, transparency, expressive geometry, and complex internal structures makes this a particularly interesting crystal for discerning collectors.

Natural specimens combining an attractive termination, appreciable transparency, and such an expressive morphology are especially sought after for their aesthetic and crystallographic interest.

This remarkable Herkimer diamond belongs to the family of double-terminated quartz crystals, whose most attractive specimens are prized for their natural terminations at both ends, brilliance, and crystal geometry. It is a superb example of this fascinating mineral formation.


Technical Specifications


- Commercial name: Herkimer Diamond
- Mineralogical nature: Natural double-terminated quartz
- Origin: Pakistan
- Weight: 11.88 carats (2.376 grams)
- Dimensions: 16.5 × 14.4 × 8.6 mm
- Color: Colorless, with slight internal nuances
- Transparency: Transparent to translucent depending on the area
- Crystallization: Double-terminated, with a particularly expressive pyramidal termination
- Morphology: Natural crystal with multiple faces and crystalline reliefs
- Luster: Vitreous, particularly brilliant on the crystal faces
- Inclusions: Dark inclusions, veils, and natural internal fractures
- Condition: Natural raw crystal
- Hardness: 7 on the Mohs scale
- Intended use: Mineral collection, crystallography, and display


A Fascinating History – The Famous Herkimer Diamonds


The history of Herkimer diamonds goes back several centuries, although their geological formation is infinitely older.

Their name comes from Herkimer County, located in New York State, United States, a region that has become world-famous for its natural double-terminated crystals.

These mineral formations are associated with dolomitic rocks dating back approximately 500 million years, to the Cambrian period.

In these ancient formations, natural cavities allowed particularly remarkable crystals to develop.

Unlike crystals that grow directly on a rock matrix, some specimens were able to grow freely in these spaces, allowing terminations to form at both ends.

This distinctive feature gave rise to crystals with fascinating natural geometry.

The region’s Indigenous peoples knew about these crystals long before they became widespread in modern mineral collections.

Over time, their transparency, brilliance, and visual resemblance to certain precious stones earned them their famous name.

Herkimer diamonds gradually gained an international reputation among collectors, crystallography enthusiasts, and admirers of natural minerals.

Today, the name remains closely associated with double-terminated crystals featuring particularly attractive morphologies.

Their history perfectly illustrates the fascination exerted by natural crystals whose geometry seems to have been sculpted with extraordinary precision.


A Complex and Particularly Attractive Crystallization


This specimen immediately stands out for its remarkable crystal architecture.

Its upper section features an elegant pyramidal termination, formed by sloping faces that converge at a clearly visible natural point.

This termination is one of the piece’s most appealing features.

It contrasts with the lower section, whose structure appears more complex, with numerous reliefs, intersecting faces, and variations in transparency.

This arrangement creates a particularly expressive silhouette.

The different natural faces reflect light at various angles, gradually revealing the details of the crystallization.

Some surfaces have an intense luster, while others allow the structures inside the crystal to be seen.

The formation of such geometry results from complex natural processes.

Crystal growth depends in particular on the availability of mineralizing elements, physico-chemical conditions, and the space available to the crystal as it develops.

As these parameters change, they can influence the final shape, reliefs, and internal features.

This specimen admirably illustrates this diversity.

Its well-defined upper termination and detail-rich lower structure give it a particularly remarkable visual identity.


Exceptional Transparency Revealing a Fascinating Inner World


One of the main attractions of this Herkimer diamond is its beautiful transparency.

Light passes through several areas of the crystal, revealing a complex array of internal structures.

Some areas are especially clear, while others display veils, natural fractures, and small dark inclusions.

This diversity creates fascinating visual depth.

Viewed from different angles, the internal structures seem to overlap, creating beautiful three-dimensional effects.

The crystal faces act as little natural windows through which to explore the inside of the specimen.

The visible inclusions bear witness to the different conditions encountered during the crystal’s formation and geological evolution.

They may correspond to trapped mineral matter, growth discontinuities, or other natural features.

These elements contribute to the specimen’s identity and add further interest for mineralogical observation.

The combination of transparent areas and complex internal structures creates a particularly attractive contrast.

Every change in orientation reveals new details, making this crystal fascinating to observe under suitable lighting.


A Geological Formation Requiring Particular Conditions


The growth of double-terminated crystals is a particularly interesting mineralogical phenomenon.

For a crystal to develop two opposing terminations, it generally needs enough open space to grow in multiple directions.

Natural cavities found in certain rock formations can provide these conditions.

Fluids rich in mineralizing elements then circulate through the available spaces.

When conditions become favorable, the mineral matter begins to organize itself into a regular crystal structure.

This growth can continue over long geological periods.

The final shape depends in particular on the environment, the flow of fluids, and any interactions with other minerals.

Some crystals develop particularly symmetrical terminations.

Others have more complex shapes, secondary reliefs, or characteristic internal structures.

This specimen belongs to the latter aesthetic category, combining a highly expressive upper termination with a crystal architecture rich in detail.

The complexity of its morphology is a remarkable testament to the natural phenomena responsible for its formation.

A true work of natural crystallization, shaped by geological processes that are impossible to reproduce identically.

An 11.88-Carat Specimen with a Remarkable Presence

With its 11.88 carats, this Herkimer diamond has a particularly appreciable weight for an individual crystal.

Its dimensions of 16.5 × 14.4 × 8.6 mm give it a generous silhouette, making its various features easy to observe.

Its natural shape has an appealing aesthetic balance between the upper point, the lateral faces, and the reliefs of its lower section.


The crystal is particularly distinguished by:

- A superb natural pyramidal termination.
- Complex crystallization with multiple faces.
- Beautiful transparency across several areas.
- Intense reflections on the crystal surfaces.
- Particularly expressive natural architecture.
- Fascinating internal inclusions and veils.
- An elegant geometric silhouette.
- A remarkable weight of 11.88 carats.
- Dimensions of 16.5 × 14.4 × 8.6 mm.
- An authentic, individual mineralogical character.

These features make this specimen particularly interesting for a collection of natural crystals.

Its transparency and morphology can be appreciated both with the naked eye and under magnification.


A Unique Piece for Discerning Collectors


Mineral collectors pay particular attention to specimens with attractive crystallization, beautiful transparency, and expressive geometry.

Double-terminated crystals hold an interesting place in this field because of their instantly recognizable morphology.

Every specimen has its own characteristics.

Some are prized for their clarity, others for their symmetry, inclusions, or the complexity of their growth.

This specimen brings together several of these qualities.

Its particularly elegant upper termination immediately catches the eye, while its many internal structures invite closer inspection.

Its natural reliefs and many brilliant faces give it a remarkable presence.

Displayed in a mineral cabinet, it makes an attractive and interesting piece to study.

Observing it under different lighting gradually reveals the many distinctive features of its structure.

A magnificent specimen for lovers of complex natural crystallizations and minerals with a strong visual character.


Conclusion – A Remarkable Natural 11.88-Carat Herkimer Diamond


This superb natural 11.88-carat Herkimer diamond, measuring 16.5 × 14.4 × 8.6 mm, is a beautiful collector’s piece thanks to its remarkable crystallization, transparency, and particularly expressive natural architecture.

Its elegant pyramidal termination, multiple brilliant faces, and fascinating internal structures give it a unique appearance.

The combination of its generous size, complex geometry, and many natural features makes it a particularly appealing specimen for mineralogy enthusiasts.

A magnificent collector’s piece, combining the beauty of natural crystallization, the brilliance of remarkable crystal faces, and all the fascination of an ancient geological formation.




General Terms and Conditions of Sale – MineralsOpals:

At MineralsOpals, your satisfaction is our top priority.

All orders are handled with the utmost care, from selecting the stones to final dispatch.


- Shipping & delivery times:

Dispatched within a maximum of 1 to 3 business days, usually the day after the order is placed.

Shipping Monday to Friday (excluding weekends and public holidays).

Every parcel is sent via La Poste with a tracking number provided.

Careful packaging: each stone is individually protected and then placed in a sturdy, secure cardboard box.


- Guarantee & customer service:

100% of shipments are guaranteed: if there is a problem, we will always find a solution.

Buy with confidence: full refund, replacement, or a goodwill gesture in the event of loss or a confirmed problem.

If you have a question, a concern, or a specific request, you can contact me at any time. I’ll be happy to respond as soon as possible.

Trust & commitment
Every stone is carefully photographed to reflect its natural beauty.

You receive personalized support.

My goal: to offer you a reliable, personal, and transparent shopping experience.

Thank you for your support.

Feel free to browse our no-reserve auctions to discover other exceptional products, and follow us to stay informed about our new listings.