17.04 Ct. Topaz from Ceylon (Sri Lanka)

This exquisite transparent 17.04 carat oval blue topaz measures 18.03 by 13.11 by 9.14 millimeters and is presented in a classic mixed brilliant cut. The mixed brilliant cut combines a brilliant-cut crown with a pavilion that incorporates step or modified facets, designed to balance maximum face-up spread with lively scintillation. This specific stone displays intense color saturation, an excellent polish, and a clarity grade recorded as very, very slightly included when evaluated at eye level, which for practical purposes means the stone appears clean to the naked eye with only microscopic or minute inclusions visible under magnification. Originating from Ceylon, Sri Lanka, and enhanced by irradiation, this topaz represents a large and beautifully finished example of color-enhanced blue topaz that offers a striking presence in any jewelry design where a substantial, vivid blue focal gem is desired.

From a gemological perspective, the combination of weight, cut, clarity, and polish are the primary determiners of the visual success and market value of a stone like this. At 17.04 carats, the stone provides significant face-up area and presence, which is further optimized by the oval outline and the mixed brilliant facet arrangement. The excellent polish enhances surface lustre and optimizes light return across the crown facets, while the mixed-cut pavilion ensures a pleasing balance of brilliance and broad flashes rather than a facet pattern that only favors return through tiny pinpoint scintillation. The clarity designation very, very slightly included indicates high internal purity relative to most commercial topazes, meaning the stone will exhibit superior transparency and minimal internal obstruction to light travel. The irradiation enhancement used to produce the intense blue is a standard, stable, and widely accepted treatment for blue topaz; it yields durable color that does not require special recharging, and subsequent controlled heat treatment is commonly applied to achieve the final desirable hue and stability.

When comparing reflective qualities to other gemstones in the same blue category, topaz occupies a characteristic niche. Natural blue topaz has a refractive index of approximately 1.61 to 1.64 and a relatively low dispersion of about 0.014, so it will not display the same level of fire or spectral flashes as high dispersion stones like zircon or diamond. Compared with aquamarine, a beryl with an RI near 1.57 to 1.58 and lower dispersion, blue topaz generally offers more apparent brilliance and a crisper facet contrast due to its slightly higher refractive index and typically cleaner material. Against blue sapphire, which has an RI of about 1.76 to 1.77 and greater refractivity, sapphire will deliver stronger brilliance and saturation per unit of color, but quality large sapphires of this size and clarity are exceedingly rare and command far higher prices. Blue zircon, when available in good clarity, outshines topaz in fire and brilliance because of its higher dispersion, but zircon is softer and can be more brittle and subject to alteration under heat. The mixed brilliant cut of this topaz enhances its perceived brilliance relative to step-cut aquamarines and promotes lively scintillation that competes favorably with many alternate blue gem options in everyday jewelry wear, while still offering superior durability with a Mohs hardness of about eight, making it well suited to rings and pendants with mindful setting.

For the educated buyer considering long term satisfaction and aesthetic return, several factors make this piece notable. The Sri Lankan provenance offers an additional provenance premium, as Ceylon has a long history of producing finely formed crystals and skilled cutting, which contributes to the clean appearance and well-executed proportions seen here. While irradiation is the standard enhancement route for blue topaz and should be transparently disclosed, it is stable and accepted by trade and collectors; the primary value drivers then remain carat weight, color intensity, clarity, cut quality, and polish, all of which this specimen presents in an exceptional combination. From a practical standpoint, the stone’s excellent polish and mixed brilliant design will maximize light interaction in typical lighting environments, producing bright face-up appearance and lively movement without the excessive dispersion that can sometimes overpower a design. Care is straightforward, warm soapy water and a soft brush are recommended, and ultrasonic cleaning is generally acceptable for topaz provided there has been no recent exposure to heat or other treatments; The Natural Gemstone Company can provide guidance on cleaning and setting recommendations. For setting, the oval outline and substantial dimensions make this topaz ideal for a solitaire ring with protective prongs or a bezel for everyday wear, a halo to amplify perceived size and brilliance, or a pendant where the full depth of the stone and its scintillation can be appreciated.

In summary, this 17.04 carat Ceylon blue topaz from The Natural Gemstone Company is a fine example of a large, transparent, intensely colored, and well-finished gemstone. Its mixed brilliant cut and excellent polish deliver pleasing brilliance and scintillation that, while different in character from higher dispersion gemstones, provide a bright, lively, and elegant presence suitable for both statement and classic jewelry designs. The combination of very, very slightly included clarity at eye level and the proven provenance of Sri Lanka positions this stone as an attractive purchase for knowledgeable collectors and discerning buyers who value transparency in enhancement disclosure and a balance of size, color, and cut quality. If you would like detailed documentation, magnified images, or individualized advice on mounting styles that will best showcase this gem, The Natural Gemstone Company is available to assist with certification and bespoke setting recommendations.