Weights of Common Substances
Compiled by Andrew Roy The table below provides density figures for many common (and some not-so-common) substances. This information is useful for determining the weight (or volume) of objects and cargo. This table was pieced together from a wide variety of sources, listed in full at the bottom of the page. The inspiration for this comes from the old Dragon magazine article, "How Heavy is My Giant". These figures have not been rigorously checked. Do not rely on this as a scientific reference! Note on measures: Specific gravity is a measure of an object's density. A cubic centimeter of water at 4°C weighs 1 gram, and has a specific gravity of 1. The specific gravity numbers below can be read as "grams per cubic centimeter" (or kg/liter). A solid object with a specific gravity greater than 1 will sink in water. Weight in pounds per cubic inch and foot is also provided to save non-metric users some time on the calculator. Material Specific Gravity Pound
I'm not sure which map you have, but the world has probably gone through four or five redesigns since I first put it together back in the early 90's :) Mainly I've done it because I grew dissatisfied with what I'd built and decided to create something better (though I usually keep particular elements from incarnation to incarnation). I've actually recently come up with a "protomyth" to incorporate into the setting that explains the changes (really, it's always been intended ;) ).
This latest incarnation I'd intended to be the last, since free time is a much rarer commodity than it used to be. And it did last quite awhile...but there's actually another version on the way. I didn't intend for that, but I'll have a blog post accompanying the posting of the map and PDF that explains the rationale.
But this time will be the last...