in case of heterogeneous pegmatite try to avoid quartz cores, it's do not include graphical texture in feldspar parts. To geochronological studies, you can use zircon by La-ICPMS, hand picking minerals such as muscovite and feldspars will be useful to K-Ar  dating in the case of the late pegmatites fluids in normal cooling ratings.

Pegmatites typically contain the monazite. You can use electron microprobe for monazite dating (see for example Gonçalves et al . Chemical Geology 424 (2016) 30–50

Hi Ahthony,

Do your pegmatites have rare-metal minerals such as columbite, tantalite and cassiterite? You could obtain the U-Pb ages of these minerals by LA-ICP-MS dating. If your samples are not rare-metal pegamtite, you could date on monazite by U-Pb method. Zircons in most pegmatites are radiation-damaged, i.e. their U-Pb systems are disturbed. It is very diffcult to get precise U-Pb ages of zircons from pegmatites.

Coltan (columbite and tantalite) U-Pb dating:

Ore Geology Reviews 65 (2015) 979–989

In situ U–Pb isotopic dating of columbite–tantalite by LA–ICP–MS

Ore Geology Reviews 64 (2015) 667–719

Tantalum–(niobium–tin) mineralisation in African pegmatites and rare metal granites: Constraints from Ta–Nb oxide mineralogy, geochemistry and U–Pb geochronology

https://www.researchgate.net/publication/310811466_Age_of_the_Dahongliutan_rare_metal_pegmatite_deposit_West_Kunlun_Xinjiang_NW_China_Constraints_from_LA-ICP-MS_U-Pb_dating_of_columbite-Fe_and_cassiterite

Cassiterite U-Pb dating:

https://www.researchgate.net/publication/280311486_Dating_cassiterite_using_laser_ablation_ICP-MS

Ore Geology Reviews 43 (2011) 235–242

Regards, Rongqing

Article Dating cassiterite using laser ablation ICP-MS

Article Age of the Dahongliutan rare metal pegmatite deposit, West K...

Re-Os in molibdenites is a possibility in case of their presence in these pegmatites.