microfelsitic
/ˌmʌɪkrə(ʊ)fɛlˈsɪtɪk/Geology
adjective
Of a rock: showing signs of incipient crystallization without there being any actual crystals; cryptocrystalline.
Origin
Late 19th century; earliest use found in Frank Rutley (1842–1904), geologist. From micro- + felsitic, after German mikrofelsitisch.