Quoting from a reliable source, the Ark was made of acacia wood overlaid with gold.

Also, the depiction here is highly likely to be wrong, especially since the rings are said to be on the feet!

It was 2.5 cubits long, 1.5 cubits wide and high. Above the chest was the Mercy Seat, upon which were a pair of cherubim shrouding the ark.

There were four cast gold rings on the feet, in which were placed gold-overlaid acacia carrying poles.

Converting from cubits to feet, using 18″ per cubit, the chest portion of the Ark was 3.75′ (45″) by 2.25′ (27″) by 2.25′ (27″). For sake of argument, I am going to presume the boards were 2″ thick. Acacia has a good density, at roughly 650kg per m³, or about 40.6lbs per ft³, or about .373 oz per in³. 3.75*2.25*4 (if the Mercy Seat was actually gold overlay on acacia) + 2.25*2.25*2 is a total of 43.875, or 43 7/8 ft² of acacia boards (the 4 sides, bottom, and mercy seat area). That is a total of about 25 pounds of wood (rounding) for the Ark proper.

I am going to presume a 1/32″ layer of gold within and without for the overlay. There is no set of dimensions given for its thickness in the Bible, so I’m giving a generous guess. Gold is roughly 11.16 ounces per cubic inch. Given the above dimensions, there are approximately 87.75 ft² of gold to be applied to the chest. At 1/32″ all around, that is approximately 395 in³ of gold needed, or about 275 pounds. Perhaps this thickness estimate is wrong, but it is a starting point.

The cherubim are described as being of hammered gold. I don’t know if they were to be solid or not, but I will guess if they are roughly cylindrical, and about4″ in diameter and 18″ long, they would weigh 158 pounds each. That has to be a wildly-off guess, so let’s say they were each 1/3 that size, or about 52 pounds each.

Now we need the cast rings on the feet. Let’s say the poles are two inches in diameter, plus their gold overlay, so the rings need to be about 2.5″ ID. Maybe they were 3.5″ OD and 5″ long. That would give a total weight of gold needed for each ring of nearly 40 pounds. That seems too high, but as a rough guess it’s a starting point.

This gives a total weight of the materials of the Ark, using the above assumptions, of about 565 pounds. The estimates of the weight of the cherubim and gold overlay may be off by as much as a factor of two – but 565 pounds is still quite maneuverable by four men using poles. Also, it is plausibly light enough to be “steadied” by a man seeing it totter on a cart.

Also inside the Ark were the Tables of the Law, an urn of mana, and Aaron’s rod which budded. I would guess their total weight at under 50 pounds.

This would give a maximum plausible weight of the Ark of the Covenant at approximately 615 pounds, or roughly 160 pounds per man on the poles.

Using half the gold, and thinner boards, the total weight of the Ark, including its sacred contents, would be closer to 330 pounds, or about 85 pounds per man.

What a sight the Ark must have been!

As an interesting sidebar, acacia wood is aromatic, and has been used in forms as preservatives and pharmaceuticals for thousands of years. Additionally, the branches are thorny on most varieties.