12.94 Ct. Topaz from Brazil

This specimen presents as a transparent Swiss blue topaz weighing 12.94 carats, with precise dimensions of 13.90 by 13.70 by 7.50 mm, cut in a classic Asscher style within an octagon outline. The presentation of the stone is defined by its step faceting, where concentric square tiers on the crown descend to a fairly broad table, and parallel pavilion facets terminate in a well proportioned culet area. Clarity is graded as eye clean, evaluated at normal viewing distance, and the polish is excellent with facet junctions meeting cleanly and consistently across the girdle. Color is intense, saturated Swiss blue, uniform across the stone with no visible zoning, a quality achieved and stabilized by controlled irradiation enhancement. Origin is Brazil, a source known for producing topaz crystals that combine good size with favorable crystallographic development. The refractive properties of topaz, including a relatively low dispersion, mean that color and clarity are primary drivers of the gem visual appeal, and in this piece the Asscher faceting strategy emphasizes depth of tone and internal luminous planes rather than scintillation, yielding a composed and architectural visual effect.

The journey of this topaz begins in Brazilian pegmatitic and pneumatolytic environments where late stage fluorine rich fluids fostered the growth of well formed prismatic topaz crystals. Field extraction was conducted by experienced teams operating under modern small scale mine protocols, using controlled blasting and careful hand extraction to preserve crystal terminations and minimise surface damage. Once removed from the matrix, each rough crystal was inspected for inclusion pattern, color response to light, and natural habit. Rough pieces showing favorable symmetry or the potential for large yield were set aside, and this particular rough demonstrated a nearly equant habit, ideal for an octagonal Asscher plan. Early stage sorting at the mine site prioritised stones with homogeneous tone and minimal cleavage plane stress, a selection criterion that reduces loss during cutting because topaz exhibits perfect basal cleavage requiring careful orientation when faceting.

In the cutting studio the rough was oriented with exactitude, the pavilion angles calculated to balance internal reflection with table brightness given topaz refractive index near 1.61 and low dispersion. The Asscher cut was executed as a high precision step cut, employing a square pavilion in octagonal outline, with broad bezel facets on the crown and multiple concentric steps that create the signature hall of mirrors effect. Facet angles were machineset and hand finished to maintain symmetry across all eight bezel facets and sixteen pavilion steps, control that yields consistent light return and edge crispness. The cutter aimed for a depth percentage that preserves weight while avoiding a windowed effect, using the final proportions 13.90 by 13.70 by 7.50 mm to secure a balance between face up size and optimal light performance. Surface finishing employed progressively finer abrasives to achieve an excellent polish, and final inspection verified that facet junctions are tight, table parallelism is within strict tolerance, and the girdle exhibits even thickness. The irradiation enhancement followed industry standard protocols to produce the intense Swiss blue hue, and subsequent annealing steps were controlled to ensure color stability and to minimise surface stress.

From studio to market the piece underwent full traceability and quality control by The Natural Gemstone Company, including documentation of origin, a record of the enhancement method as irradiation, and photographic documentation at multiple angles to illustrate cut symmetry and color saturation. Gemological review confirmed the eye clean clarity, and packaging included handling recommendations that note topaz relative hardness and basal cleavage sensitivity, advising settings that protect the girdle area and avoid extreme localized heat during jewellery construction. The Natural Gemstone Company sources with an emphasis on ethical procurement, and this stone retains chain of custody documentation from extraction through cutting and enhancement to final inventory status. For collectors and designers who appreciate technical detail, the Asscher cut Swiss blue topaz is presented as a study in proportion and optical intention, a gem that translates geological history into a prepared form ready for contemporary jewellery. For enquiries about mounting options, independent gemological reports, or bespoke setting recommendations, The Natural Gemstone Company will provide measurements, facet diagrams, and photographic files to assist in selection and design.