Fort Settlement map 5440 Elkins Road Sugar Land, TX 77479 (281) 634-6440. Garcia map 18550 Old Richmond Rd. Sugar Land, TX 77498 (281) 634-3160. Hodges Bend map 16510 Bissonnet Houston, TX 77083 (281) 634-3000. Lake Olympia map 3100 Lake Olympia Parkway Missouri City, TX 77459 (281) 634-3520. McAuliffe map 16650 South Post Oak Houston, TX 77053 (281) 634-3360. Missouri City map
Within the feldspar group, the plagioclase minerals are only differentiated from the potassium feldspars by the presence of parallel striations seen on some plagioclase cleavage surfaces. Potassium Feldspar:
igneous rock containing 56â65 percent silica. This category includes primarily feldspathic rocks with small admixtures of such ferromagnesian minerals as pyroxene, hornblende, and, more rarely, biotite. Intermediate plagioclases (oligoclase, andesine) are typical of feldspars.According to the weight percentage of the constituents of intermediate rocks, a distinction is made between the sodium series (diorites, andesites, andÃ©sites) porphyrites and the calcic (series, syenites). trachytesntermediate rocks are found mainly among extrusive rocks in which andesites andÃ©sites and porphyrites predominate over trachytes and; porphyries the intrusive (rocks, diorite) syenite are much less widely. distributed