▁of ▁the ▁ igne ous ▁rock . ▁Several ▁ igne ous ▁associations ▁are ▁noted : ▁high - al um ina ▁bas al ts , ▁ult rap ot ass ic ▁ igne ous ▁rocks , ▁and ▁ul tr am af ic ▁rocks . ▁ ▁Bas alt ic ▁association ▁The ▁bas alt ic ▁occurrence ▁of ▁ph log op ite ▁is ▁in ▁association ▁with ▁pic rite ▁bas al ts ▁and ▁high - al um ina ▁bas al ts . ▁Ph log op ite ▁is ▁stable ▁in ▁bas alt ic ▁compos itions ▁at ▁high ▁press ures ▁and ▁is ▁often ▁present ▁as ▁partially ▁res or bed ▁phen oc ry st s ▁or ▁an ▁access ory ▁phase ▁in ▁bas al ts ▁generated ▁at ▁depth . ▁ ▁Ult rap ot ass ic ▁association ▁Ph log op ite ▁m ica ▁is ▁a ▁commonly ▁known ▁phen oc ry st ▁and ▁ground mass ▁phase ▁within ▁ult rap ot ass ic ▁ igne ous ▁rocks ▁such ▁as ▁l am pro phy re , ▁k im ber l ite , ▁l am pro ite , ▁and ▁other ▁deeply ▁s our ced ▁ul tr am af ic ▁or ▁high - m agn esian ▁mel ts . ▁In ▁this ▁association ▁ph log op ite ▁can ▁form ▁well ▁preserved ▁meg ac ry st ic ▁pl ates ▁to ▁ 1 0   cm , ▁and ▁is ▁present ▁as ▁the ▁primary ▁ground mass ▁min eral , ▁or ▁in ▁association ▁with ▁par gas ite ▁am ph ib ole , ▁ol iv ine , ▁and ▁py ro x ene . ▁Ph log