Marblewood

Geographical Distribution

The wood most commonly known and sold as Marblewood is known to botanists as Zygia racemosa. Sometimes, it may still be referred to by the now outdated classification Marmaroxylon racemosum. The Zygia genus contains slightly over a dozen known species, all of them native to Central and South America. Z. racemosa is found in northern South America where it is endemic to French Guiana, Guyana, Suriname, Venezuela, Colombia, and Peru. However, despite its larger range, Z. racemosa on the United States market is almost always imported from Guyana or Suriname. European markets, especially French markets, are more likely to feature wood harvested in French Guiana for reasons of trade agreements, tariffs, and shipping routes.

To further confuse matters of identification, some retailers also sell Zygia cataractae, usually known as “Tigre Caspi,” as “Marblewood.” While clearly related, Z. cataractae is not identical to Z. racemosa. Z. cataractae, harvested in Brazil exclusively, is much rarer than Z. racemosa and therefore usually more expensive.

However, with that said, the woods are very similar in appearance and it is practically impossible to tell the two apart without resorting to genetic testing, which is impractical for most wood workers, nor is it necessary as neither species, at this time, is subject to restrictions on export or sale.

For the sake of simplicity, I will refer to Z. racemosa from this point forward as Marblewood.

Marblewood Bowl Top

Marblewood Bowl Top

General Characteristics

The heartwood of the Marblewood tree is where the action is, so to speak. While the sapwood is usually much the same distinctively yellow color as the heartwood, only the heartwood features the highly distinctive stripes, ranging in color from yellow, golden, or dark brown, to even purple or black. These streaks are what woodworkers are after when using this wood. The streaks have no relation to growth rings and are completely random in appearance, thickness, and density. Every piece of Marblewood will feature different stripe patterns in varying colors. These stripes cause Marblewood to bear a superficial resemblance to Zebrawood, but the two woods are otherwise very different. Any woodworker who has worked with both species will be able to tell them apart quite easily.

Marblewood Bowl Sidewall 1

Marblewood Bowl Sidewall 1

The grain of Marblewood timber tends to be straight although slight interlocking is not unknown. The wood features a medium texture with very open pores. The pores can be quite large and may require filling, especially on the endgrain sections, if a completely smooth finish surface texture is desired.

Marblewood end grain shows diffuse and porous medium to large pores in no specific arrangement. There are frequently considerable deposits of a yellowish substance found in the end grain pores. Growth rings are indistinct and as noted before, the stripes bear no relation to growth rings.

While it probably doesn’t have relevance for the uses of Marblewood outside of its native range, Marblewood is considered to be durable to very durable in its resistance to rot, as well as moderately resistant to insect attack.

Working Characteristics

Everything about working with Marblewood revolves around its incredible hardness and density. The density is obvious when the woodworker picks up a piece and notes how heavy the wood is relative to its size. This hardness and density causes many woodworkers to consider Marblewood to be difficult to work with. Marblewood will have a moderate, or more likely, severe blunting effect on tools. Frequent re-sharpening, or the use of replaceable cutters, that are then frequently replaced, will be absolutely essential to being able to work with Marblewood not only successfully but at all. Tools that are inadequate to the task will simply bounce over the surface with the wood showing no evidence of any attempt to modify it.

Fortunately for me, the hardness and density of Marblewood make it an excellent turning wood, provided that tools adequate to the task are employed.

Fortunately, once the cutting operations are done, Marblewood consents to gluing and finishing quite nicely.

Care must be taken when working with the green wood as there is a high likelihood that Marblewood will exude resin and/or check (crack) during drying. Dense woods are notoriously slow to dry and Marblewood will be no exception. It may be one wood that is best allowed to dry completely, so that checks can be identified, cut out, or worked around, instead of investing considerable effort in the green turning process only to have resin and cracking ruin the work.

To add to the pleasures of working with Marblewood, many users have reported that there is a distinctive, although usually faint, odor present while Marblewood is being worked.

Marblewood Bowl Side Wall 2

Marblewood Bowl Side Wall 2

Pricing

Marblewood comes from a fairly small area of the South American continent, regardless of which species is being identified and sold as Marblewood, so users should expect prices to be at least moderate if not high when compared to other exotic imported hardwoods.

I always recommend both West Penn Hardwoods and Bell Forest Products as excellent sources of both domestic and exotic hardwoods. I have had multiple dealings with both vendors and have always been very satisfied.

West Penn Hardwoods has decent stocks of Marblewood in bowl and spindle turning stock, including pen blank, sizes, as well as thin dimension lumber. As a price example, a very large 8x8x3 bowl blank of Marblewood currently sells for slightly over $30. This price seems, to me, to be rather low for a wood reported to command high range pricing; you certainly can pay a great deal more for other exotic hardwoods of that size. Also, please note that West Penn Hardwoods is listing their Marblewood as Tigre Caspi (Z. cataractae). Stock photos show wood that looks very similar to the Marblewood I worked with, but I wouldn’t swear to the species level identification of this, or any other dealer’s, stock.

Bell Forest Products does provide a listing for two spindle sizes of Marblewood, but they are currently out of stock. They do, however, have some stock of dimensional lumber available, 4/4, for $25 per square foot.

While the two dealers above are personal favorites, Marblewood should be readily obtainable from other dealers in tropical hardwoods, probably including one near you. If you don’t have a favorite supplier that you have worked with extensively in the past, by all means shop around for the best prices and the best selection to meet your particular wood working needs.

Woodfinder is an excellent website that is dedicated to advertising exotic wood dealers. In your search for Marblewood, this can be an invaluable resource provided you use multiple search terms to capture all the possible listings. I can’t speak to the quality of any of the listed dealers, but Woodfinder does have the advantage of allowing searches to be performed based on location which might allow an interested buyer to visit a listed wood dealer near their home in person to hand pick nice pieces at a comfortable price.

Marblewood Bowl Bottom

Marblewood Bowl Bottom

Uses

The most common uses of Marblewood outside of its native ranges include, but are certainly not limited to: Flooring, sliced veneer, turned objects, cabinetry, and fine furniture. These are familiar uses for fine and highly sought after tropical hardwoods. Perhaps Marblewood is fortunate in that it is not considered to be a tone-wood, suitable for musical instruments, because tone-woods tend to be among the most highly endangered woods.

Sustainability

At this time Yucatan Rosewood is not listed in the Convention in International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendices nor does it appear on the International Union for Conservation of Nature (IUCN) Red List.

However, some authorities claim that the Marblewood tree is at risk due to habitat loss and overharvesting. It is hard to know how severe these stresses are, if they actually exist, as the most frequently referenced conservation bodies do not speak to the status of Marblewood at all.

I purchased the pieces of Marblewood that I have in stock long before I was aware that there might be any over-exploitation or concern about the future of species. Perhaps the lack of knowledge concerning tropical wood species was a benefit of being new to the hobby of wood turning.

Ideally, the loss of a species is slowed or halted long before it becomes necessary to include it in the CITES Appendices, and I am hopeful that Marblewood will never appear on the lists of restricted woods, regardless of whether I would choose to work with it again, but rather because I hate to see any species pushed into threatened status

I also realize that inherent in working with wood is the killing of a part of the natural world that may be slow to return and if I become deeply concerned about this fact, I will have to find a new hobby. I hope that such a time does not come to pass or at least not any time soon. I am also very confident that the vendor from whom I purchased my stocks of Marblewood sourced their material legally and responsibly. In part because I am concerned about legally and responsibly obtained exotic wood, I am reluctant to buy from sellers outside of well-established and known vendors. I am highly unlikely, for example, to purchase exotic wood from auction sites, such as Ebay, because of uncertain sourcing and documentation, as well as the potential, even likelihood, of material being misidentified in order to achieve a higher selling price.

It realize that many, if not most, wood workers do not have endangered species lists memorized, therefore I think it worthwhile and important to do even a small amount of research before purchasing any lumber, domestic as well as imported, to be certain of the potential impact you are having, even in a small way, on threatened or endangered populations. This information is easy to come by and takes only minutes to locate through any Internet search engine, including those you can access on your phone as you are standing in the lumber yard or store. Unfortunately, you simply cannot count on a vendor to tell you a product they are selling is endangered.

Health Hazards

There are no known or reported adverse health effects associated with the use of Marblewood. However, the standard risks posed by prolonged and repeated exposure to dust from any wood species also exists with Marblewood and steps should be taken to avoid prolonged dust exposure. In addition, appropriate protective equipment is always recommended when working with this, or any other, exotic wood, unless you have worked with the species before and are certain you are not sensitive to it.

Complete information about health hazards associated with a wide variety of exotic hardwoods is available from The Wood Database. Additional information about how to best use a dust collection system and personal protective equipment, such as respirators, can also be found through this excellent and comprehensive resource.

Fortunately, I have experienced no negative side effects when working with Marblewood.

My Personal Experiences

The first thing I noticed about the Marblewood bowl blank I was working with, when I cut it on the band saw, was that not only was it hard and therefore slow to cut, but it also had a tendency to splinter along the cut lines. This tendency was not a marked as with Wenge, but it was notable.

Once I had the Marblewood blank mounted on the lathe, its hardness became readily apparent. The wood cut slowly and with effort, but it was also very stable and very thin cuts and thin walls were possible. Because of the density of the wood, and because of the depth of the piece I was working with, about 3 inches, I cut a larger than usual divot for mounting the SuperNova 50mm chuck that I would use once the piece was taken off the face-plate and reversed to allow for cutting out the heart of the bowl.

Once I started the hollowing process, it was relatively slow going because of the hardness. The dulling effect on the carbide cutters, fortunately replaceable, of my Easy Wood Tools rougher and finisher, was extremely pronounced. I had to rotate the cutter on the finisher once during the hollowing operation and then I had to actually replace the cutter completely on both the full-size and the miniature finishers in order to continue to make any cuts at all. I have never worked with woods that had such a rapid and devastating effect on cutter heads, and I have worked with woods even harder than Marblewood, but which do not appear to have as pronounced a dulling effect. I would strongly advise potential users of Marblewood to have either sharpening equipment and experience, or to have replaceable cutter heads on hand prior to attempting to work with this wood.

I noted a distinct odor when cutting the Marblewood and I didn’t personally find it to be pleasant. It was relatively subtle but still noted.

Once cut, the wood sanded quite easily but required little sanding because quite clean cuts were possible due to the hardness of the wood. There were small areas of the end-grain that required more work than some other areas, but even this was not over burdensome. The wood rapidly took on a very nice smooth texture even with relatively low grit sandpaper. Higher grits seemed to have mainly served the purpose of polishing the very hard wood.

While I had been using straight shellac to finish bowls, other than rosewood ones, I decided to continue to experiment with the cream version of Shellawax. Shellawas is an Australian product I have used extensively before on smaller items, and I was enormously pleased with the lustrous result. The product couldn’t be simpler and easier to use. I simply dipped a clean lint-free rag into the cream and rubbed it all over the bowl, with the lathe off. Then with the lathe turned back on, I used the wet area of the rag to apply pressure while moving back and forth over the treated areas. The frictional heat created a very nicely glossy finish in seconds. The Shellawax, as the name implies, is a combination of shellac and natural waxes. I am beyond pleased with the results of this finishing product on Marblewood. The manufacturer claims that their “gimmick” is that their product works, and I couldn’t agree more!

While working with Marblewood presented some challenges due to the density and hardness, overall I was quite pleased with the outcomes. The finished bowl has a very nice appearance and heft. The dark streaks, which I think are quite purple, provide wonderful contrast against the otherwise yellow wood. I don’t believe that I have any more bowl blank pieces of Marblewood in my stocks but I may have to change that based on this recent experience, my first working with bowl blank sizes of Marblewood, although I have made pens from the material in the past. I rate Marblewood as a winner in my book!

Multiple images of Marblewood can be viewed here.

As always, I wish all my readers a great experience in whatever their wood working interests happen to be and to those who like working with lathes especially, do a good turn today!