Rock Tumbling Tips for the Hardness of a Lace Eye

Hardness

• Lace eye agates, like all agates, have a hardness of seven and can be safely tumbled along with quartz and jasper pieces. The trick is to make sure that all the rocks in one tumbling batch have the same hardness rating. As an example, tumbling lace agate with obsidian, a softer rock with a hardness rating of five, will cause the obsidian to chip and crack.

Size And Shape

• Once you have your lace eye sorted with rocks of similar hardness, make sure you have rocks of varying sizes. Smaller rocks help the grinding action by hitting against the larger rocks and helping to smooth them. Agates tend to fracture along uneven lines. Don't tumble stones that have obvious fracture lines or protrusions. The fracture lines may trap grit that can't be washed away, or the rock may break. The protrusions may break off during the final stages of the tumbling process and scratch the other stones. In either case, you will have to re-tumble the entire batch. Commercially packaged tumbling rough has already been sized and shaped. It is safe to add lace eye agates to this mixture. There may be some of these lacy rocks already included.

Tumbling Your Lace Eye Agate

• Tumbling is the process of taking rough rock and turning it into a polished stone. The rough rock is placed inside the barrel of a tumbling machine along with a series of grits going from rough to fine. As the barrel turns, the rocks and the grit grind against each other. The coarse grit shapes the rock. Two cycles in medium grit follow to take out the leftover scratches. Finally the rocks and tumbler are thoroughly cleaned and then a polishing compound is used in the barrel to put a shine on the rocks. The last step is to tumble the rocks with soap to clean off any excess polishing compound. Each step or tumble takes about a week. Since lace agate is a hard rock it may take longer to smooth the rough edges and polish the stone. Some of the tumbling steps may need to be repeated until you are happy with the result. This is where one of the most important tools for rock tumbling--patience--comes in handy.