Dims: 1.7 x 0.6 x 0.4" (4.3 x 1.5 x 1.0 cm)
Wt: 6.0 g w/ base
Mt. Ste. Hilaire, Quebec, Canada
This small specimen consists of a cluster of long, prismatic Natrolite crystals that extend off of the edge of a small crust. These crystals achieve lengths of up to 1.5" (3.8 cm) and are generally in excellent condition; only two show any obvious breakage, and these are not easily noticeable. The crystals have very good orthorhombic form, with moderately well-defined edges and clean though heavily striated faces. The prism faces are quite dull due to their striations and have a dull pearly-to-waxy luster, whereas the termination faces are quite clean and possess a bright vitreous luster. The Natrolites have a rather dull, pale-gray coloration that appears to be caused by the inclusion of a dark substance. This color deepens very slightly towards the base of the cluster, and renders the crystals translucent to dimly transparent, whereas they would nominally be quite transparent. However, they all appear to contain substantial internal fracturing, which also provides interference. The crust off of which the cluster grows is coated with scores of tiny Natrolites that have a much darker gray coloration. These needles to not exceed 2 mm in length, and are thus not easy to see without magnification. The specimen arrived to us glued onto a square acrylic base, and I believe that it is too delicate to separate it.