1.47 ct Unheated Yogo Sapphire — GIA Origin Report

Collector's Note
A rare American sapphire from Montana's famed Yogo Gulch, this 1.47 ct natural blue sapphire combines strong saturation and high transparency with the collector appeal of GIA-confirmed origin and no indications of heating. Faceted Yogo sapphires above one carat are notably scarce, making its size and locality the defining features of this stone.

Gemstone Details
Gemstone: Natural Blue Sapphire
Species: Corundum
Weight: 1.47 ct
Shape / Cut: Oval Modified Brilliant Cut
Measurements: 7.10 × 6.46 × 3.61 mm
Color: Blue
Transparency: Transparent
Origin: USA (Yogo Gulch), Montana
Treatment: No indications of heating
Condition: Surface scratches and abrasions are present; professional repolishing is recommended.

O50 Collector Evaluation
Otzera 50: 36/50 — Distinguished
Face-Up Performance: 70%

Treatment & Origin Disclosure
GIA determined the geographic origin to be USA (Yogo Gulch) and reported no indications of heating.

Laboratory Documentation
Accompanied by GIA Sapphire Origin Report No. 5221467846, dated June 8, 2022.

Provenance / Collector Significance
Yogo sapphires are prized for their highly specific Montana provenance and are typically encountered in small sizes. A faceted Yogo above one carat is particularly uncommon, giving this stone meaningful locality and size appeal for collectors of American gemstones.

Care & Setting
Sapphire is durable for jewelry wear, but this stone currently shows notable facet-surface wear. Professional repolishing is recommended before setting. If repolished, the stone should be reweighed and remeasured and its documentation reviewed for consistency.

Digital Gem Passport
Accompanied by an Otzera Digital Gem Passport preserving its identifying details, GIA documentation, treatment and origin disclosures, condition notes and O50 evaluation.