I
C
Cut
The single characteristic that determines a diamond's optical life. We favour precision proportions over spread — brilliance and fire read across the room before any grading report is opened.
House Chapter IIDiamonds
Diamonds selected as objects,not as inventory.
Every diamond in our cabinet is natural — examined in person, evaluated against independent laboratory reports and admitted only when character, cut and provenance meet the standard of the house.
Assurance of the house
- GIA / IGI / HRD certification
- 360° video & full documentation
- Fully insured worldwide delivery
- 14-day risk-free return
- Responsibly sourced · Kimberley compliant
Independently verified by
Chapter IQuick entry to the catalog
Diamonds by cut
Select a cut and step straight into the house's curated catalog.
Plate ISenior Gemologist · House of SOSNA Diamonds
Chapter IThe House Standard
A diamond is admitted, not acquired.
The house evaluates each diamond as an object of study — cut, proportion, optical return, provenance and documentation — before price is ever discussed.
- 01
Independently certified
GIA, IGI, HRD, SSEF and Gübelin — reports issued and verified for the specific specimen.
- 02
Cut before carat
Optical performance and proportion evaluated first; carat is a consequence, never the objective.
- 03
Natural origin only
The house presents natural diamonds exclusively — no laboratory-grown, no synthetics. Origin and any treatments disclosed in writing.
- 04
Human review
No stone enters the cabinet without in-hand review by a senior gemologist of the house.
Chapter IIThe Four C's
Cut. Colour. Clarity. Carat.
The house reads the four characteristics in strict order — cut first, carat last. Nothing enters the cabinet on carat alone.
II
C
Colour
Graded D–Z on the standard scale, but read in daylight against a neutral tray. We rarely accept anything below G unless a fancy colour justifies its own reading.
III
C
Clarity
Inclusion character matters as much as grade — nothing eye-visible in the face-up view, nothing that disturbs the return of light through the crown.
IV
C
Carat
A measure of weight, not of quality. Presented last for a reason — after cut, colour and clarity have already been judged on their own terms.
Plate IINatural Round Brilliant · Macro Study
Chapter IIIWhich diamond are you looking for?
Three routes into the cabinet.
A short path from intention to the right stone — investment discipline, colour rarity, or the exceptional single-piece.
IPlate · 01
Investment diamonds
Strict quality parameters and internationally recognised certification. Suited to those who value stability and long-term worth.
IIPlate · 02
Fancy colour diamonds
Natural stones of exceptional colour and character — for collectors seeking something genuinely singular.
IIIPlate · 03
Exceptional diamonds
Larger sizes that captivate at first sight — presence for a defining moment, value that endures.
PL · 02Atelier · St. Petersburg
Chapter IIIProvenance & Disclosure
Natural diamonds only — always disclosed, always documented.
The house presents natural diamonds exclusively. We do not trade laboratory-grown or synthetic stones under any circumstance. Every diamond arrives with its natural origin certified, any treatments (or their absence) recorded, and its independent laboratory report on file — before a client ever sees a price.
- Independent laboratory report on every stone
- Certified natural origin — no laboratory-grown, no synthetics
- Written disclosure of any treatments — laser drilling, fracture filling or colour/clarity enhancement
- Documented chain of custody from atelier to client
Chapter IVFor US Clients
Direct delivery to the United States — handled by the house.
Discreet, fully-insured logistics tailored to US collectors. No sales tax on direct-to-collector shipments handled from our atelier; import formalities and settlement managed end-to-end.
- 01
No US sales tax
Direct-to-collector shipments handled by the house incur no US sales tax at point of sale.
- 02
Fully insured worldwide
FedEx Priority or Brinks Global Services — signature on delivery, all-risks insurance in transit.
- 03
Wire settlement above $3,000
Bank wire preferred above $3,000. Direct acquisition to $25,000; above this figure, private terms on request.
- 04
14-day re-appraisal
Fourteen-day return period; independent US re-appraisal (GIA, AGS) welcomed and expected.
Chapter VHouse Assurance
Questions collectors ask us first.
Short answers to the questions that matter before an acquisition.
Are the diamonds natural?
Exclusively natural. The house does not trade laboratory-grown or synthetic diamonds under any circumstance. Natural origin is certified in writing for every stone.
Which laboratories do you accept?
GIA, IGI, HRD, SSEF and Gübelin. Reports are issued and verified for the specific specimen and travel with the stone.
Can I have the stone re-appraised in the US?
Yes — independent re-appraisal within the 14-day period is welcomed. We can suggest GIA-affiliated appraisers in your city on request.
How is payment handled above $3,000?
By bank wire in USD or EUR. Direct acquisition to $25,000; larger transactions on private terms after due diligence.
Is the diamond conflict-free?
Every stone in our cabinet is Kimberley Process compliant with documented chain of custody from atelier to client.
House Advisory
Speak with a diamond specialist.
Every inquiry is handled personally by a senior gemologist of the house. We advise on characteristics, provenance, laboratory reports and comparable market context — always in strict confidence.