Cancrinite is – or rather was – a common mineral at MSH. However, all of the very large (several cm) crystals have been replace by analcime and other minerals. Unaltered cancrinite can still be found as fairly large masses in the sodalite syenite, but unaltered crystals, even small ones, are rare and are found almost exclusively in the very uncommon sodalite xenolith environment. This specimen is from such a xenolith. It was analyzed via XRD and EDS at Laurentian University in 2008, and found to be “cancrinite group”, possibly hydroxycancrinite. Hydroxycancrinite would be new mineral for MSH, but detailed chemistry was not done, so this remains just a possibility. (If you have access to WDS, here is your chance to add to the MSH species list!) Note: This specimen is ex Ron Waddell, whose label says UK53/53A – which would be malinkoite or a related mineral, but apparently that is not the case.
The first pair if photos shows colorless, transparent, crystals of “cancrinite” ca 1.3 mm long, with “eudialyte group” crystals to ca 1.2-1.3 mm. (In the absence of detailed chemistry, it is impossible to say which EGM species is present. Visual ID is totally useless at MSH, and even EDS is generally insufficient – although in some cases this can provide a fairly good indication or at least narrow the possibilities.) The cancrinite crystals look somewhat like apatite.
The second pair of photos (FOV 2.4 x 3.4 mm) shows another, well-terminated, but stubby, cancrinite crystal 0.8 mm in diameter. In this view, the long dimension of the eudailyte is ca 1.5 mm.
The next photo is a close-up of this cancrinite crystal. (It’s an old photo and the color balance isn’t quite right.)
The next pair of photos (FOV 4.6 x 6.6 mm) shows the crystals from the first pair of photos in the lower tight corner, along with a larger, cloudy white, crystal to ca 2.5 mm. (I’m not sure if this is “cancrinite” or some other mineral.
There is also a bit of villiaumite, as can be seen in the full-view photo.
Single item shipping weight (no case) is 2.9 oz. Outside the USA, the stated postage and packing rate applies up to a total weight of 8 oz (225 g).
Within the USA, there is a nominal increase of $0.20 for each additional ounce. Above 13 oz, I will use Priority Mail. Up to 16 oz, the “own box” Priority rate is $9.25 (including packing).
