An intrusion composed of rock described as litchfieldite occurs at Morro da Estrela, 45 km northwest of the town of Porto Nacional. The rock comprises 40-65% albite/oligoclase, 3-30% microcline, 15-30% nepheline, which is partly replaced by cancrinite and zeolite, 0-15% biotite and accessories including sodalite, cancrinite and rare fluorite.
MARCHETTO, C.M.L. 1973. Nota sobre a ocorrencia de um litchfieldito no Morro da Estrela, Municipio de Porto Nacional (Goias). Anais Congresso Brasileiro de Geologia, 27: 85-6