CompuServe Messages

Hi, David– Welcome to the forum/section! The Lapidary Journal of Aug 93 has an article on gem feldspars – your town library may have back issues. 60% of earth's crust is feldspars, a group of which labradorite is a member. It is quite common, but only rarely does it take on gem quality. Thus its value may be anything from zero to significant, depending on color, visual texture, and freedom from flaws. Many labradorites are accounted gems because they show a schiller called labradorescence; the prize among these is Finnish "spectrolite", a variety of labradorite. "Madagascar labradorite" is technically andesine, a very similar feldspar showing this schiller. Oregon sunstone is another form of labradorite showing "aventurescence", a glitter caused by large numbers of tiny flat metallic inclusions. A lesser kind of sunstone is found at many other locations – this is technically oligoclase, yet another feldspar. But these feldspars are easily confused, and yours may not be technically labaradorite, even though someone calls it that – these minerals shade into one another and are very hard to distinguish, and it is not critical to gem value anyway. What counts is color, luster, etc. Not being a lapidary, I could not guess on prices. If anyone here knows enough, they will surely need to know something about the color, the visual texture (labradorescence, aventurescence, etc.), transparency, etc. Telling us where it is from, if you can, may help. –Doug