NT89S5: Transparent and bright rhombohedral crystals with very well defined phantom growths in some of their faces. The interpenetration twin is specially sharp and underlined by fine horizontal striations.
Asturreta Quarry, Eugui, Esteríbar, Comarca Auñamendi, Chartered Community of Navarre (Navarre)  Spain

Specimen size: 6.3 × 4.6 × 2.8 cm = 2.48” × 1.81” × 1.10”