Blue and light-blue spinel from Tanzania

Octagon-cut cobalt blue spinel 1.05 carats, Tanzania

Rare electric blue cobalt spinel from Tanzania in oval cut 5.34 ct

Cobalt blue spinel in octagon cut from Tanzania 1.49 carats

Set of cobalt blue spinels in pear cut 2.02 carats, Tanzania

Blue cobalt cushion cut spinel 1.50 carats, Tanzania

Intense cobalt spinel in radiant cut 1.12 ct, Tanzania

Blue oval cut spinel 1.16 ct, Tanzania

Octagon cut cobalt blue spinel 1.35 ct, Tanzania

Cobalt blue spinel from Tanzania 3.51 ct

Cobalt blue spinel 2.45 carats, Tanzania

Unique octagon cut cobalt spinel 1.65 ct, Tanzania

Heart cut blue spinel 3.36 ct, Tanzania