petrified wood 6: Australia, South East Asia                                         

11. Australia

Australia is well known for every good opals but also for very good petrified wood (most Araucaria, less Osmundai- a fern and Pentoxylon) and opal wood. The most popular petrified forests are located in Queensland and Tasmania. The petrified wood dates back to Jurassic times. Some special type of petrified wood comes from the northwest of Australia (region around Carnavon). This wood is known as “peanut wood” or “teredo shipworm wood”. It looks just like a bit of peanut brittle, but is in fact, "teredo-bored petrified wood". This interesting material is ancient wood that becomes waterlogged and later sinks. Before being fossilized the wood is invaded by one of several species of mollusc larvae (ship worms by today's equivalent). Here in the wood they bore holes to live. Later these holes are filled in with radiolarite (diatomaceous earth or micro marine animal skeletons). Like other petrified wood it is buried and is fossilized by agate or other minerals. Peanut wood is sought at for its polka-dot patterns and its genuine uniqueness as a cutting rough and fossil specimen.

Pentoxylon is a very rare gymnosperm, so far only found in the southern hemisphere. It has bee named "five-wood", because the stem is not made up of a single wood body. Mostly it's made up by 5 or 6 wood bodies. The wood bodies are embedded in bark. Every wood body has growth rings and therefore was adding to the thickness of the stem. Probably Pentoxylon was a development coming from Palaeozoic Medullosa and ending in the Jurassic period.

complete round (ca. 300 x 300 mm)

 

(ca. 110 x 200 mm)

(ca. 200 x 250 mm)

"Penutwood" (ca. 120 x 70 mm)

12. South East Asia (Indonesia)

Once in a while petrified wood from Indonesia is shown on the rock shows. The wood is from the  Tertiary geologic age. The wood seems to be not very hard because the slices get no real good polish.  From outside colour of  the logs is light brown with some black. But after cutting they often change complete into black colour. But I've also very nice petrified wood with some jasper or quartz. Sometimes after cutting a log you can see something coming from another world.

unknown with natural structure on an angle (ca. 130 x 100 mm)

hardwood (ca. 100 x 80 mm)