Batch 87: Inspiring a Potential Rocktumbler

It is a treat to have company during a fossick and to potentially inspire a new rocktumbler! My company was Lucy, our neighbour’s daughter and she had asked me a while a go if she could come with me the next time I go to Gemstone Beach. It’s taken a few failed attempts (she’s a busy young lady) but finally our schedules aligned (thanks School Holidays) and we were able to do a fossick at Gemstone Beach.

Lucy is no stranger to collecting rocks and stones as she often goes to the beach with her family and is always picking up things interesting to her. However, this was her first time crossing the Taunoa Stream and walking all the way down to the Waimeamea River and back! She did really well and found some cool stones!

This trip to Gemstone Beach with Lucy is also the fossick that starts a new series that I’m going to be posting throughout this year and next. Find out more here!

October - Gemstone Beach — Lucy fossicking up the side of the Waimeamea River

Lucy’s Stones

Batch 87 are the 87 stones (not intentional to have that number) that Lucy picked out from all her finds from our Gemstone Beach fossick together. We looked at all her stones using the wet method, the sun and a torch to help her decide which ones she wanted to see tumbled.

There were 12 hydrogrossular garnets amongst her finds. I only showed her what they were a couple of times so well done Lucy plus 18 more stones have been put aside to skip Stage 1 because they are already super smooth. They’ll hang out in the readies drawer and rejoin her batch at Stage 2 with the first lot of stones.

Batch 87: 6lb Tumbler 2

Stage 1: F60grit

Number of Stones: 75+12=87
Weight in: 1513g
6 Tbspns of F60grit
2 Tbspn Borax
Plastic Pellets (needed to make up the load)
Days Tumbling: 10
Weight out: 1383g – loss of 130grams

Note: Slurry was unusually gritty after Stage 1

Stage 2: 220grit

Number of Stones: 87+18=105
Weight in: 1550g
6 Tbspns of 220grit
2 Tbspn Borax
Plastic pellets added
Days Tumbling: 11
Weight out: 1250g – loss of 300grams

Note: Not a close inspection done as I’m keeping these stones together for Lucy

**Stage 3: *600grit**

Number of Stones: 105+2=107
Weight in: 1295g
6 Tbspns of 600grit
2 Tbspn Borax
Ceramic media added
Days Tumbling: 7
Weight out: g – loss of grams

*Decided to skip 400grit and do 600grit for Stage 3 instead. I didn’t want Lucy’s stones to loose more volume than necessary but some still weren’t quite ready enough. Most of the stones Lucy chose are a type of mudstone (sedimentary) so they are softer than the usual Gemstone Beach suspects. Needed both small and big ceramic media to help make up the load for the 6lb barrel.

Pre-polish Soap Tumble: 24 hours

Batch 87: After Stage 2

B87 after 220grit — Lucy’s stones after Stage 2 – most are either argillite, mudstone, or quartz. Can you spot the cool trace fossil?

Batch 87: Added to Stage 3

Adding B87 — Two stones (below tray) added to 600grit as they are super smooth and don’t need much time tumbling in grit

Ready to Polish – Transfer to 4lb Tumbler 1

By the time Lucy’s stones were ready for polish they had significantly decreased in volume due to their mostly sedimentary nature. Therefore I made the decision to switch them over to the 4lb Tumbler to polish.