This is a mound of brilliant white, sharp, lustrous, blocky laumontite crystals. On close inspection with magnification, one can see that some of the crystals are actually in slightly diverging groups, rather than single crystals. In excellent condition. Collected by Terry Collett in 2020, this is a very fine laumontite.
About These Laumontite Specimens
Laumontite is a relatively common zeolite group mineral (that can occur in excellent specimens!) but because it usually dehydrates relatively quickly in air (and can then turn to powder), it is not so commonly preserved and encountered in mineral collections.
These laumontite specimens have been stabilized. After experimentation with various methods and materials, it has been found that a technique using a mixture including water-soluble glue is the most effective, with no impact on the visual appearance of the specimens (colour or lustre). Nova Scotia laumontite specimens stabilized using this method have proven stable over longer than 20 years, with no indication that such stability will change (in mineral cabinets, at approximate normal indoor humidity levels – ranging from approx. 25-75%). Specimens in my own collection are as good as the day they were stabilized.