Opal Pendant - Height: 4 cm - Width: 2.5 cm- 10.8 g - (1)

This natural Blue Opal pendant, cabochon-cut and set in 925 sterling silver, is up for auction. The piece comes from an old stock batch, predating the current boom of reconstituted, dyed materials or outright counterfeit pieces that have saturated the market.

We are looking at an authentic mineral gem, selected by visual appraisal and basic gemological criteria, suitable for both collecting and use in fine jewelry.

A distinctive and uncommon detail: it incorporates the articulated “buche” clasp (trumpet/funnel-type bail), a mark of quality and of old-stock origin. It improves the pendant’s drape and reduces twisting, helping the piece stay facing forward (avoiding the back from showing), something highly valued by women and collectors.

In addition, the chaton-style setting (the classic jewelry mount) provides security, presence, and a professional finish; today it is seen mainly in well-made pieces or in higher-end jewelry.

Dimensions and weight
Total weight: 19.8 g

Dimensions of the cabochon: approx. 4.0 × 2.5 cm

Thickness: approx. 0.5 cm

Mounting: 925 sterling silver

Type of hitch: “Buche” articulated (better drop and less rotation)

Mineralogical identification and chemical formula

Opal is hydrated silica (mineraloid), with an amorphous or microcrystalline structure. In the case of Blue Opal, the color may be due to microinclusions, light dispersion, and/or mineral traces (depending on provenance), giving those soft transitions like a “cloud” that are observed in natural material.

General formula of opal:

SiO₂ · nH₂O (hydrated silica)

Hardness (Mohs): approx. 5.5 – 6.5 (variable depending on water content/structure)

Typical density: approx. 1.9–2.3 g/cm³ (may vary due to porosity and water)

Visual / geological reading of the piece

In this piece you can see a blue with internal variations, with lighter areas and denser ones, forming cloud-like effects and natural transitions. This visual behavior is consistent with genuine opal: imitations tend to exhibit flat color, too uniform, or with artificial tints.


The polishing reveals a vibrant surface, without the plastic-like appearance seen in resins or composites. The cabochon has a presence and a highly marketable commercial format due to its clean, bright aesthetics.

Authenticity and tests performed

Given the current market context—especially the proliferation of reconstituted/dyed opal—practical controls have been considered and applied:

Test with acetone (control of surface staining):

There is no color transfer or 'staining' typical of dyes.

Scratch resistance (consistent with opal):

The piece exhibits hardness compatible with opal (it does not behave like soft resin).

Observation with a magnifying glass (control of artificial porosity / bubbles):

With a loupe, look for the telltale signs of fakes: bubbles, uniformly round pores, a “plastic” pattern or layered appearance. The visual reading is consistent with polished natural stone (not an injection-like look).

Structure and natural chromatic transition:

The cloud-like internal variations and the “depth” of the material are more consistent with natural opal than with glass or synthetic material.


Reasonable conclusion: natural blue opal, with no clear signs of surface dyeing or composites at a glance.


(Professional note: the exact density would require volumetric measurement; here we provide the standard mineralogical range and visual criteria + practical tests.)

Origin, provenance, and historical context of the opal


Opal has been valued since antiquity for its relation to light, water, and mystery. In different cultures it was regarded as a stone of protection and prestige; in later periods it came to symbolize rarity and "organic" beauty due to its hydrated nature and optical behavior.


Blue Opal, in particular, has become highly valued in contemporary jewelry for its clean, elegant aesthetics. In the current market, finding convincing, well-crafted material is becoming increasingly difficult due to the massive influx of imitations.

Properties (collector's approach and jewelry)
Aesthetic: soft blue with a cloud-inspired look, highly sought after for its elegance and ease of pairing.

Mineralogy: hydrated silica; material sensitive to extreme handling (like any opal), which makes it even more interesting for collectors who value well-preserved pieces.

Collectible value increases when the piece is solid, with good carving, polishing, and mounting in real silver.

Old remittance, market, scarcity and investment

This jewel comes from old stock (old stock): that matters because many old stock shipments come from eras with less counterfeiting and less pressure from mass production. Today the market is saturated with reconstituted, dyed, or fake merchandise, and that creates a clear effect:

The real thing is becoming rarer,

The informed buyer looks for evidence and coherence,

and the real material, well described and verifiable, tends to appreciate in value due to trust and rarity.


In a market contaminated by imitations, a convincing piece, well put together and properly explained, behaves like a tangible asset: beauty + authenticity + demand.

And yes: behind every real mineral there is human effort. The extraction and sorting at the source require the hard work of miners and complex supply chains; recognizing it is also part of an honest sale.

Condition of preservation
Condition: excellent, ready for use or collection.

Stone with proper polishing, no visible damage.

A firm and well-executed mount (chatón)

Articulated “buche” hitch: higher drop and less twist.

Positioning and Sales Policy

It is not offered as a 'clearance'. We work with several platforms and know the real demand for authentic mineral jewelry. In the current context (scarcity + widespread counterfeiting + general rise in metals and gems), this type of pendant is positioned as a curated piece, not as a cheap product.

Conclusion
Natural blue opal pendant (SiO₂·nH₂O) in a large cabochon format, with the characteristic “cloud” aesthetic of authentic material, mounted in 925 sterling silver, bezel setting and an articulated “buche” bail that enhances drape and prevents twisting. Origin from an antique shipment, an additional value factor in a market saturated with imitations.