Cov khoom siv no yog siv los tshem tawm cov hlau nplaum tsis muaj zog, cov hlau nplaum xeb thiab lwm yam khoom paug los ntawm cov ntaub ntawv zoo.
lwm yam uas tsis yog-metallic ntxhia kev lag luam, kev kho mob, tshuaj, zaub mov thiab lwm yam lag luam.