Never thought I’d be polishing a “dinosaur egg” – well not really but that’s what this stone has affectionately come to be known as. “Dinosaur Egg” was entrusted to me by Hannah. I think she found the “perfect egg shaped stone” down at the Waikoau River Mouth where she was surfing with a couple of friends. I think the stone is actually a type of granite with quartz but don’t “quote” me on that!
Rockhound, Mike Rhea says ….
Quartz usually appears in granite as translucent, light gray, or off-white. In polished granite (as you have likely seen in countertops) it sometimes feels like you can see below the surface of the rock. This is because the quartz crystals are transparent or translucent, allowing you to see through them. Some varieties may have more impurities which make the quartz crystals an opaque gray or white color. In any case, quartz is a significant contributor to granite’s overall light color.
Mike Rhea https://rockhoundresource.com/
I decided to give the 19 Moeraki Stones one more go through all the tumbling stages as well as adding some of the stones (10) picked up at Gemstone Beach by my Aunt and Uncle who stayed with us for a few days back in October along with 30 stones from my fossicking at the same time.
Tumbler: 3lb Tumber 2
Stage 1: 80/100grit
Number of stones: 60
Total Weight: 933g
Dinosaur egg weight: 125g
4 Tbspns of 80/100grit – no pellets added
Days tumbling: 12
Weight out: 827g – loss of 106g
Dinosaur egg weight out: 114g
Stage 2: 220grit
No stones were removed or added.
Weight in: 827g
4 Tbspns of 220grit – no pellets added
Days tumbling: 11
Weight out: 737g – loss of 90g
Dinosaur egg weight out: 106g
Noticed a few “chips” in the bottom of the tumbler after cleaning out the 220grit mix.
Stage 3: 400grit
No stones were removed or added.
Weight in: 737g
4 Tbspns of 400grit – pellets added to help cushion.
Days tumbling: 14
Weight out: 647g – loss of 90g
Dinosaur egg weight out: 98g (that’s total loss of 27g in the grit tumbling process).
All stones transferred to the 4lb tumbler for polishing.
Tumbler: 4lb Tumber
Stage 4: Polish | Stage 5: Borax
Combined with Batch 12 using 600ml of polish mix (on it’s 3rd re-use). I’m still not 100% sure of just how good the polish mix is on re-use.
Number of stones: 120 (41 from Batch 12 tumbled in 3lb Tumbler 2 + 19 Moeraki stones + 60 stones from this batch – Batch 13)
Weight in: 1919g – pellets added.
Days tumbling: 14
Weight out: 1795g – loss of 124g. (I didn’t think the stones would lose so much during the polish tumble but obviously they do!!)
The dinosaur egg lost another gram and now ways 97g – but it sure is smooth and shiny! You can see a few little pits in the image to the right but those aren’t really visible to the naked eye.
I was really pleased (as was Mat) with how the Moeraki stones turned out. Although they did take three times as long as other stones to tumble, they do look really good – especially when you shine a light on them. (Did I do that – yes – and remembered to take a photo – nope!)
Achei todo o processo muito interessante, tenho uma pedra muito parecida com o ovo de dinossauro, foi achada em um rio em Peruíbe, São Paulo, Brasil, parece muito improvável existirem 2 dessas pedras na natureza, em lugares tão distantes.
Olá Pablo
Obrigado por deixar um comentário. É fabuloso que você também tenha uma pedra de ovo de dinossauro!
Espero ter traduzido isso corretamente para você!