gems, spinel, inclusions

Red spinel from Vietnam’s Luc Yen district contains layers of iridescent hogbomite needles within dislocations, resembling a futuristic skyline. Such hogbomite-filled dislocations are common in red, pink, and blue spinel from Vietnam. Hogbomite, with the chemical formula (Mg,Fe)₂(Al,Ti)₅O₁₀, occurs in spinel through isomorphous replacement.