This is one of the best cabinet specimens from the 2021 Stronach Brook find. It is a large plate with two mounds of crystals at the top (or one side, depending on how you orient it). The crystals are sharp with good lustre, and with magnification one can easily see the classic monoclinic form of termination, with one large sloped face and one much smaller triangular one opposite (the latter is not always evident). In excellent condition – a few crystals are incomplete, but remarkable condition for the size of specimen! This is a great 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.
These excellent laumontite specimens are from a 2021 find at Stronach Brook, a locality that is usually not rich in fine mineral specimens. They exhibit the habit typical of the best Nova Scotia laumontite specimens – they are hemispheres and mounds of very sharp, bright crystals.