17.04 Ct. Blue Topaz from Ceylon (Sri Lanka)

One beautiful transparent 17.04 carat oval shape blue topaz is presented with dimensions 18.03 x 13.11 x 9.14 mm, a mixed brilliant cut, a clarity grade described as very very slightly included evaluated at eye level, intense color intensity, and an excellent polish. The proportions are especially favorable for a gem of this size, with a length to width ratio of about 1.38, and a depth that measures approximately 59 percent of the average diameter, a balance that gives this stone both a generous face up presentation and strong light performance. The color has been produced by irradiation, a standard and permanent enhancement for blue topaz when properly applied and disclosed, and the gem is documented as originating from Ceylon Sri Lanka, a source with a long history of producing richly colored and well crystallized material. The Natural Gemstone Company stands behind full disclosure of treatments and origin, and we present this topaz as a high quality specimen for connoisseurs and jewelers seeking a combination of size, color, and eye clean clarity.

A closer look at the grading elements clarifies why this specimen is attractive to an educated buyer, the clarity grade of very very slightly included at eye level indicates that the stone reads as essentially eye clean in normal viewing conditions, with only minute inclusions that do not interfere with transparency or light return, and which are difficult to detect without magnification. The mixed brilliant cut is chosen to maximize both scintillation and color concentration, using a brilliant facet arrangement on the crown to create lively flashes, and a series of step influenced pavilion facets to preserve depth of color and stability of light performance. The excellent polish produces crisp facet junctions that enhance contrast and the perception of depth, so that facet reflections remain bright and defined even in softer lighting. At 17.04 carats this topaz occupies a category of gemstone that is notable for its presence and wearability, making it ideal for statement rings, pendants, or collectors pieces where size and optical performance are both priorities.

When comparing reflective qualities to other gemstones in its category, it helps to consider refractive index and dispersion as physical controls on brilliance and fire, topaz typically has a refractive index in the range of about 1.61 to 1.64 and a modest dispersion around 0.014, values that place it above beryl family stones such as aquamarine which sit nearer 1.57 to 1.58 in refractive index, and below corundum such as sapphire which is typically near 1.76 to 1.77. What this means in practical terms is that this blue topaz offers crisper and more lively facet reflections than aquamarine because of the slightly higher refractive index, producing stronger contrast and a brighter face up appearance, while it will not show the same degree of fire as higher dispersion stones such as zircon or diamond which have substantially greater dispersion and therefore more colorful flashes. Compared with sapphire, the topaz presents a different visual appeal, with a more brilliant, almost gemmy sparkle due to its mixed brilliant cutting style and excellent polish, whereas sapphire often reads as a deeper, lustrous color with more saturated tone and greater hardness which makes it preferable for everyday wear. Compared with zircon, which can display significant fire due to dispersion values that are several times higher, this topaz trades some of that colorful flash for a richer, more saturated blue and cleaner transparency, attributes that many buyers prize for colored stones used in colored gem centerpieces.

For the buyer considering this gem for a commission or for a collection, practical considerations solidify its value proposition, the size 17.04 carats combined with intense color and eye clean clarity places it in a category that is attractive to collectors and designers who want an impressive face up size without sacrificing optical quality. Its Mohs hardness of about 8 gives it good resistance to daily wear, though it is less hard than sapphire or diamond, so protective settings that shield the girdle and corners are advisable for ring applications destined for everyday wear. The irradiated color is stable under normal conditions and is industry standard for producing the vivid blue hues associated with blue topaz, and The Natural Gemstone Company fully discloses this treatment while providing additional imagery and documentation on request. Routine care is straightforward, using warm soapy water and a soft brush to maintain brilliance, and avoiding prolonged exposure to extreme heat or harsh chemicals. For buyers who prioritize provenance, the Ceylon Sri Lanka origin adds a layer of desirability, and for those focused on optical performance, the mixed brilliant cut, the excellent polish, and the eye clean clarity combine to deliver a gem that performs with crisp reflections, strong face up color, and an overall presence that makes it a compelling choice for high quality bespoke jewelry or a specialized gemstone collection.