NBF76AO5: Orthoclase crystal with very sharp faces and edges and a very well defined double Baveno-Manebach twin.
The specimen comes from the collection of Santiago Jiménez who, especially in the 1980s and '90s, put together an excellent collection with a very good representation of the mineralogy of northern Spain.
Bustarviejo, Comarca Sierra Norte, Community of Madrid  Spain

Specimen size: 7.6 × 3.3 × 2.8 cm = 2.99” × 1.30” × 1.10”