Preliminary Research: Feature of Cross Section, Hardness, and Specific Gravity Some Petrified Wood from Loa Janan, Kutai Kertanegara, East Kalimantan

Nani Husien, Agus Sulistyo Budi, and Gandi

Laboratory of Information and Woody Plant Biology, Forestry Faculty, Mulawarman University, Indonesia

Abstract: The aim of this research is to identify some petrified wood discovered in Loa Janan district of Kutai Kertanegara East Borneo, for anatomical feature in the cross section, the hardness and the specific gravity as well. It was hypothesized that the petrified woods which were discovered would be endemic hardwood species from East Borneo. Six specimens with different size were taken and grinded with different grit (16 to 60). A binocular microscope was used to observe pattern of pores, rays, including resin ducts. Digital balance and measuring glass was used to determine the specific gravity, while selector diamond was used to determine hardness. Reference identifying was used to identify the wood species or genus. Result showed that all specimens were macroscopically identified as Fossil of hardwood, they were characterized by the existence of growth ring, pores, and rays. Most solitary pores grouping filled with mineral deposits were apparent in all of fossil woods. The diversity of color line was probably based on its formed minerals. The hardness of specimens were between 3 to 6 mosh, and were based on the color. The specific gravity of specimens were between 1,715 g/ml to 6,050 g/ml. The Important thing, that based on identification result, the biggest petrified wood which discovered in Loa Janan district of Kutai Kertanegara is most likely species of cf.Leptospermum family Myrsinaceae.

Key words: petrified wood, specific gravity, hardness, eusideroxylonzwageri , cf. Leptospermum