Batch 63: Gemstone Beach Hydrogrossulars

Most of the 65 stones in Batch 63 are Gemstone Beach hydrogrossulars apart from a couple of quartzites (?) and a jasper. They had been sitting in the readies drawer probably having already been identified as smooth enough to skip Stage 1 and Stage 2. It is possible however that the argillites, jasper and other stones that aren’t hydrogrossular had a tumble in the 12lb barrel in F60grit and/or 220grit previously.

My good rockhounding friend JP has a great post here on why hydrogrossular garnets are found in Nelson and Orepuki that is worth a read.

I am already finding it difficult to track a batch of stones like I used to, especially if they tumble in the QT12 barrel for more than just Stage 1. My current thinking is that I will only tumble Stage 1 stones in the 12lb barrel and then make up a batch from Stage 2 onwards. If I am particular about what moves onto the next stage then it’s unlikely that a batch of stones will change much (other than the odd stone removed or added) from Stage 2 (220grit). That will make it much easier to track the batch.

Batch 63: 3lb Tumbler 4

Stage 1: 80/100grit

Batch 63’s stones came out of the readies drawer. As most are hydrogrossulars or argillite it’s probable that they skipped Stage 1 and Stage 2 altogether. No specific data available.

Stage 2: 220grit

As per Stage 1

Stage 3: 400grit

Number of Stones: 65
Weight in: 824g
3 Tbspns of 400grit
1 Tbspn Borax
Ceramic media added
Days Tumbling: 8
Weight out: 762g – loss of 62 grams

Pre-polish Soap Tumble: 3 hours to ensure that they are free from grit before going into polish. Even after 3 hours the water was quite grey! I use 2 tspns of grated sunlight soap plus water for this tumble.

Batch 63: Ready for Stage 3

B63 Gemstone Beach — From the Ready for 400grit drawer – most of these are hydrogrossular garnets that probably skipped Stage 1 and 2. Some of the top stones are argillite (also super smooth already) and some are quartzite(?)

Batch 63: After 400grit

B63 after 400grit — Although wet, the stones are starting to get a shine on them.

Ready to Polish

For this batch I did not premix the Tumble Polish powder and water. I’ve been following some rocktumblers on Instagram for a wee while now and as I watch their reels, they just add the powder straight into the barrel. I thought I would try this too!

I am also using less powder than I normally would if I was to go a 300ml water/powder mix. Usually I put 5 Tbspns of powder into 300mls of water. This time I am using the barrel ratio: 3lb barrel = 3Tbspns plus water filled up to just below the surface of the stones.

Stage 4: Polish Mix

Number of Stones: 65
Weight in: 754 grams
Tumble Polish powder: 3 Tbspns of polish not pre-mixed with 300mls of clean water.
1 Tbspn borax added.
Ceramic pellets added for cushioning
Days Tumbling: 10
Weight out: 751g – loss of 3 grams

The polish mix was very grey when finished. This shows me why it’s so important to do a 24-48hour soap tumble BEFORE polish despite how well you think you wash the stones! This time I only did a 3 hour soap tumble and I now realise that this is not long enough to ensure that the majority of grit is washed out prior to polish.

Polish Complete

Batch 63 complete – many many different hydrogrossular garnet varieties

Polished Stones of Interest: Batch 63

B63 SOIs — Hydrogrossular garnet varieties! That black on on the left is my fav.

Batch63 SOI — Argillite (mudstone) with jasper trace fossils

Polish from Batch 63 — Look how grey the polish was once the stones were removed!

Batch 63 | 3lb Tumbler 4 | Gemstone Beach | pre June – 23 June 2024