Typically, if a pegmatite melt is phosphate poor, spodumene will crystallize rather than triphylite. Spodumene would then consume all the lithium. In the Black Hills there are good examples of this and I would guess this is true in other pegmatite provinces. Of all lithium minerals found in pegmatites (amblygonite-montebrasite, triphylite-lithiophilite, petalite, lepidolite, sicklerite etc) spodumene is the most important economically, although I am not sure if it is even mined with the discovery of lithium carbonate brines now developed in Chile and Argentina. A major use of lithium are the infamous lithium batteries the culprit in many aggravations from laptop to auto and now the Boeing Dream(nightmare)liner.
Lithium pegmatites constitute about 1-2% of all pegmatites in a district and most districts contain a few lithium rich pegmatites. They are typically located furthest from their apparent source. Most lithium pegmatites are sharply zoned in grain size and mineralogy with the lithium concentrated in the interior zones or cores. The Foote mine is an example of a large unzoned lithium rich pegmatite. See chapter on lithium minerals by London & Burt in Min. Assoc. of Canada short course in Granitic Pegmatites (1982) for more information.
Spodumene is a pyroxene and the crystal habit is a good indication of this. Large spodumene crystals can be found in pegmatites on the order of tens of feet. This specimen is just a nice example of this rich lithium ore mineral.
The specimen is thought to be of Paul Moore's collection portions of which were acquired by Don Phillips. The number on the label matches the specimen.