I received a specimens from Bulgaria identified as "Heulandite", but I am not sure if this is correct.
Locality: Gruevo, Kardzhali province, Rhodope Mts. Bulgaria.
It is a nodule of 1,5x2x3.5 cm. Light weight at 10 grams. At the exposing fracture it shows radiating aggregates of up to 0.8 cm diameter.
Color pinkish white. Luster is dull. Hardeness abour 4.
Wolfgang,
As you have suspected, it is very unlikely that this is heulandite. Mindat lists for this locality only radiating apophyllite. Looking at your pictures I would say it is most likely one of these:
- Natrolite and/or mesolite and/or scolecite and/or thomsonite and/or gonnardite; and/or because these radiating aggregates are probably made out of several minerals
or
- mordenite
or
- dachiardite
or
- ferrierite
Radiating apophyllite is of course also a possibility, as well as pectolite.
Only XRD (+ perhaps EDS) will give to a certain extent some idea on what it acually is.
Regards
Wolfgang
