JFD56AN9: It was always believed that these elongated black crystals were diopsides, but thanks to Gonzalo García, editor of the respected mineral magazine Bocamina, we now know that they are actually augites. In the case of this piece, it is abundant and well displayed, as there are many crystals traversing the Prehnite crystals.
Altogether, a fine piece from this locality, with the addition of the Augite and small Titanite crystals. Curiously, in the review of the piece that appeared together with its photograph in Mineralien Welt magazine, page 10 of the 01/2004 edition, the Augite is not mentioned but only the Prehnite. In those years these Carchelejo specimens were still relatively new in Europe.
Oficarsa Quarry, De las Culebras Hill, Carchelejo, Cárcheles, Comarca Sierra Mágina, Jaén, Andalusia  Spain (2003)

Specimen size: 7.7 × 6.3 × 3.2 cm = 3.03” × 2.48” × 1.26”

Main crystal size: 2.5 × 2.2 cm = 0.98” × 0.87”