Loose marquise-cut gemstone (unauthenticated)

The visual evidence presents a loose, faceted gemstone featuring a distinct marquise shape with pointed ends and a curved, elongated center. The stone displays clear refractive properties with spectral highlights and brilliance reflecting light from its crown facets. Based strictly on the visual information alone, it is not possible to distinguish between a natural diamond, a lab-grown diamond, or a diamond simulant such as cubic zirconia or moissanite. The item rests on a dark, textured blue background. The owner-supplied context describes the piece as a loose marquise-cut natural diamond measuring approximately 10mm in length by 5mm in width by 3.0mm in depth, with an estimated weight of .95 carats; however, this user-supplied attribution is entirely unverified and requires professional gemological testing, such as thermal and electrical conductivity testing or microscopic inclusion analysis, to determine the material composition and specific gemological properties. There are no visible maker's marks, laser inscriptions, or certifications captured in the photograph.

Based on what I can see in the photograph, I observe a loose, faceted gemstone featuring a marquise cut resting on a dark, textured background. The visual evidence shows clear refractive properties and brilliance, but I cannot verify material composition from a photograph alone. Per user submission, the owner identifies this as a loose marquise-cut natural diamond measuring approximately 10mm x 5mm x 3.0mm with an estimated weight of 0.95 carats. My appraisal estimate of $3,500 to $6,000 assumes that the owner's attribution is correct and that the stone is a natural diamond of comparable quality, color, and clarity. General market demand for marquise-cut natural diamonds in this size range remains steady, though pricing fluctuates based on the four Cs. I would need physical inspection, microscopic inclusion analysis, and professional gemological testing, such as thermal or electrical conductivity testing, to confirm the identity of the material. If the item turns out to be a lab-grown diamond, the market value would typically decrease significantly, and if it is a diamond simulant such as cubic zirconia or moissanite, the value would be negligible by comparison.