There is an undeniable excitement that comes with cracking open a rock tumbler after weeks of relentless grinding. The sheer transformation of rough, jagged stones into smooth, tactile treasures is impressive, but the true magic lies in the anticipation of what is uncovered when the sludge is finally washed away. In our latest tumbling session, we cracked open two of our massive barrels that have been running in 60/90 grit, sifting through the gooey mess to see what hidden masterpieces we could uncover.
The Mechanics of the Tumble: Patience and Cushioning
When you are working with large tumblers, patience and the right mix of materials go hand in hand. Both of these barrels were allowed to run quite a bit longer than a standard 10-day to two-week cycle [00:58, 07:03]. While leaving them in the rough grit longer does create a completely broken-down, sludgy mess [01:09], it doesn’t hurt the stones at all. In fact, that extended time creates an incredibly fine finish, smoothing the stones so well they feel like they are already well past the 1500-grit stage [03:13].
Another crucial step, especially when tumbling fragile materials like slabs, is ensuring you have the right ratio of filler. Tumbling delicate slices can be risky, and you are almost guaranteed to have a casualty or two break along a fracture line [12:17]. To solve this, packing the barrel with a large volume of very small, gravel-sized stones—like carnelian, rose quartz, and small tiger eye pieces [04:29, 13:29]—provides the essential cushioning power needed to protect the larger pieces from shattering against each other.
The foam you might see when opening a barrel isn’t cause for concern, either. Adding a squirt of a drying agent like Jet-Dry [07:21] helps manage the slurry and keeps the process running smoothly.
Hits, Misses, and Masterpieces
Tumbling rough rock and slabs is always a game of chance. Sometimes a piece proves to be crumbly and needs to go back into a finer grit for more smoothing [04:10], but other times, the results are simply breathtaking. Here are a few of the most striking reveals from our two barrels:
- Mexican Crazy Lace:Â We pulled an absolute showstopper from the first barrel [02:52]. The extended time in the grit perfectly smoothed the surface, revealing a stunning, intricate pattern that makes it one of the nicest pieces we’ve ever tumbled.
- Indian Bloodstone:Â The second barrel was loaded with slabs, and the bloodstone certainly did not disappoint. We found pieces with classic deep green and red combinations, as well as a striking “zebra” bloodstone [09:00] and another slab boasting beautiful, vibrant yellow hues [12:35].
- South African Tiger Eye:Â You can’t run a tumbler without some classic tiger eye! The slabs we pulled out are gorgeous [10:18], showing off brilliant flashes of color, including a spectacular piece cut from some new material we picked up in Quartzsite [11:36].
- Sodalite:Â Amidst the reds and yellows, a slab of sodalite offered a beautiful pop of rich, genuine blue [11:24].
- Mexican Parral Jasper:Â We also uncovered some wonderful slabs of Parral Jasper, featuring rich, earthy patterns [13:06].
Whether it is a delicate slab of Brazilian agate showing off incredible color [09:36] or a simple target piece getting perfectly rounded, every single barrel opening is a brand-new discovery.
If you are looking to start your own tumbling projects, be sure to browse our shop for high-quality tumbling and rough rock and cushioning gravel, and let the lapidary adventure begin!
