Choosing between a 1,720-carat rough blue sapphire and a 9.05-carat cushion-cut alexandrite is really a question of what you plan to do with the stone. In the loose gemstones and pearls category, these two natural certified stones sit at opposite ends of the spectrum: one is a massive uncut sapphire with a blue color and asterism effect, the other is a faceted color-change alexandrite in a cushion cut.
Quick Verdict
Pick the 1720 CT Natural Blue Sapphire Certified Rough Uncut Stone if you want maximum carat weight in a raw, uncut specimen. Pick the 9.05 Ct Natural Alexandrite Color Change Cushion Cut if you want a cut stone with a dynamic color-change effect.
At a Glance
| Compared | 1720 CT Rough Blue Sapphire | 9.05 CT Cushion-Cut Alexandrite |
|---|---|---|
| Listed price | USD 24.99 | USD 39.99 |
| Carat weight | 1720 CT | 9.05 Ct |
| Form | Rough, uncut | Cushion cut |
| Color | Blue | Color changing |
| Gemstone effect | Asterism | Asterism, color change |
| Country of origin | India | Brazil |
| Certification | GIR | AA |
| Clarity / cut | Eye Clean / Excellent | Eye Clean / Excellent |
Where Each Product Wins
The sapphire wins on sheer size and raw presence: 1,720 carats of blue rough stone is not something you see every day. The alexandrite wins on form and effect: it is already cut into a cushion shape and its listed effects include both asterism and color change, giving it a more dynamic appearance.
Product Notes
1720 CT Natural Blue Sapphire Certified Rough Uncut Stone Huge Loose Gemstone
At USD 24.99, this is the lower-priced stone in this pairing, and the carat count is remarkable: 1,720 carats of natural blue sapphire. It is listed in rough, uncut form with GIR certification, eye-clean clarity, and an Excellent cut grade. The reported asterism effect gives it an extra visual hook for anyone interested in star-sapphire phenomena. The main limitation is the form: a rough uncut stone is not a faceted gem. Its huge size means it is best approached as a natural blue raw specimen rather than as a ready-to-wear cut stone. If you want maximum carat weight and a substantial rough sapphire, this is the match.
9.05 Ct Natural Alexandrite Color Change Cushion Cut AA Certified Loose Gemstone
This 9.05-carat natural alexandrite is the higher-priced option at USD 39.99, but it is the only one of the pair already presented in a cut cushion form. It carries AA certification, eye-clean clarity, and an Excellent cut grade. Its defining trait is the color-change effect: the listed effects include both asterism and color change, making it a more dynamic stone than the static blue rough. The tradeoff is carat weight: 9.05 carats is dramatically smaller than 1,720 carats, which matters if you are looking for a large display stone rather than a compact cut gem. If your project needs a cut, color-changing gemstone, this one is the clear match.
Final Choice by Use Case
For a loose gemstone collection centered on dramatic size and natural rough texture, choose the 1720 CT Natural Blue Sapphire Certified Rough Uncut Stone. For a cushion-cut natural alexandrite with color-change behavior, choose the 9.05 Ct Natural Alexandrite Color Change Cushion Cut. The right pick depends on whether you want raw mass or a cut, color-changing stone.
