RockTumbler.com has a great video showing what happens inside a rotary tumbler. The clip is only 44 seconds long but it graphically demonstrates what happens if the barrel is too full and if it is not full enough. It’s conclusions are:
Barrel Too Full = No Tumbling Action
Barrel Not Full Enough = Damaged Stones
Barrel 1/2 to 2/3 Full = Great Tumbling Action
The following are a number of sources I have found useful for the beginning (and also for the not-so-novice) rock tumbler. They share a number of things in common but also often have their own unique ideas or pieces of advice. (I will add to this List as I become aware of more sources).
1) RockTumbler.com “Rock Tumbler Instructions” – A reasonably detailed set of illustrated instructions. This site is based in USA and is the commercial site of a rock tumbler gone into business. It is noted that the owners of this site “publish what we believe is the largest library on the web of articles, videos and blog posts about tumbled stones and rock tumbling”. It is a mine of information – like stumbling upon a whole beach of colourful and already-rounded stones.
2) Alan Silverstein’s site “Collected Information on Rock Tumbling” – Sections on “Quick Start (Rotary Tumbling)” (updated 2008) and “More Detailed Advice on Rotary Tumbling” (updated 2011) – A no-frills but very informative set of instructions and advice. Alan is a software engineer from Colorado, USA.
3) Steve Hart’s book, “Modern Rock Tumbling” (first published 2008) – This whole book is full of useful information and advice on rock tumbling. The middle part of Chapter three is on “Understanding the 4-Stage Rock Tumbling Process”. Available from Steve himself and from all good online book sellers for about US$25.
4) “Professional Gemstone Tumbling” by Lortone (2011) – This is the 21-page booklet that came with my Lortone tumbler when I bought it. It is a set of basic reasonably-sound instructions, a very good starting point. I have not come across a copy of this online anywhere. Note that it is different from the “Rotary Tumbler Instructions and Parts List” that also came with the tumbler and is available online on Lortone’s website.
5) Lortone’s Instruction Videos – These consist of “How to fill a Lortone barrel” and three videos of how to change a drive belt on different Lortone tumblers.
6) “Rotary Tumbling Guide” from Aussie Lapidary Forum – A more cryptic and informal set of instructions and advice but valuable in how the author shares their rock tumbling experiences and experiments.
7) YouTube series on Rock Tumbling – Constructed by a US tumble polisher who uses his tumbler a handful of times a year, this series of six videos shows how he goes through the four stages of rock tumbling, using what looks like a 4lb barrel. The fifth video shows the resulting polished stones and the sixth video discusses what he does with his stones (he’s not into jewellery making). [Added 5 July 2019]
In 2008, Steve Hart published “Modern Rock Tumbling”, sub-titled “The only complete and up-to-date guide to tumble polishing rocks and stones”. It has just become available as an e-book. I wholeheartedly endorse it. The author, from California, is a mechanical engineer in the mining industry and has a wealth of experience as a home-based rock polisher using both rotary and vibratory methods. He has a small web-based company, The Little Red Store, started in 2008, which not only sells Steve’s book and rock tumbling equipment and material but also contains some very useful technical tips for those new to modern rock tumbling.
I purchased Steve’s book from Fire Mountain Gems, a US beading and jewelry supply company, as I was not at that stage aware of Steve’s own website. I had seen the book referred to on RockTumbler.com where it is stated: “We have read every book about tumbling that we could find. From that reading we have found that there are only a few books that explain tumbling with great clarity and genuine knowledge. Of those, we believe that Steve Hart has produced the best one. It explains the tumbling process completely and provides enough detail that you should produce excellent results if you follow his instructions.”
“Modern Rock Tumbling” measures 23 cm by 15 cm and is 96 pages long. It sells for about US$25 and is great value-for-money. It is very well organised and the writing is clear and good humoured. There are colourful photographs illustrating key parts of the tumbling process.
The best attributes of this book are: it is very practical, dealing with the details of rock tumbling, and all advice is based on the author’s wealth of experience; it explains technical issues when of relevance, and Steve’s background in mining is useful here as is the range of people he has consulted in the preparation of the book; and it presents the various options available to the rock tumbler, such as types of tumblers, the various grit sizes, and the characteristics of the various polish powders. I read it after only a couple of weeks of my own tumbling venture and found it directly relevant, immediately useful, and the best I have come across.
(See the review from “Rock and Gem Magazine”, which agrees with me.)
A polished stone from Riverton beach, from my wife’s second batch, iron-stained quartzite, yellow and brown throughout:
“June Hymn” by the Decemberists
Here’s a hymn to welcome in the day
Heralding a summer’s early sway
And all the bulbs all coming in
To begin
The thrushes’ bleeding battle with the wrens
Disrupts my reverie again
Pegging clothing on the line
Training jasmine how to vine
Up the arbor to your door
And more
Standing on the landing with the war
You shouldered all the night before
Once upon it
Yellow bonnets
Garland all the lawn
You were waking
Day was breaking
A panoply of song
And summer comes to Springville Hill
A barony of ivy in the trees
Expanding out its empire by degrees
And all the branches burst abloom
In the boom
Heaven sent this cardinal maroon
To decorate our living room
Once upon it
Yellow bonnets
Garland all the lawn
You were waking
Day was breaking
A panoply of song
And summer comes to Springville Hill
And years from now when this old light
Isn’t ambling anymore
Will I bring myself to write
“I give my best to Springville Hill”
Once upon it
Yellow bonnets
Garland all the lawn
You were waking
Day was breaking
A panoply of song
And summer comes to Springville Hill
A polished stone, picked up from a Riverton beach, from my wife’s second batch of tumble polishing – the colours remind me of the Australian Outback and of Aboriginal art:
“Raining on the Rock”
by John Williamson
Pastel red to burgundy and spinifex to gold,
We’ve just come out of the Mulga where the plains forever roll.
And Albert Namatjira has painted all the scenes,
And a shower has changed the lustre of his land.
And it’s raining on the Rock,
In a beautiful country,
And I’m proud to travel this big land
Like an Aborigine.
And it’s raining on the Rock.
What an almighty sight to see!
And I’m wishing on a postcard that you were here with me.
Everlasting daisies and the beautiful desert rose –
Where does their beauty come from heaven knows.
I could ask the wedge-tail but he’s away too high,
I wonder if he understands it’s wonderful to fly.
And it’s raining on the Rock,
In a beautiful country,
And I’m proud to travel this big land
Like an Aborigine.
And it’s raining on the Rock.
What an almighty sight to see!
And I’m wishing on a postcard that you were here with me.
It cannot be described with a picture,
The mesmerising colours of the Olgas,
Or the grandeur of the Rock –
Uluru has power!
And it’s raining on the Rock,
In a beautiful country,
And I’m proud to travel this big land
Like an Aborigine.
And it’s raining on the Rock.
What an almighty sight to see!
And I’m wishing on a postcard that you were here with me.
Four stones from a Riverton beach, picked up and polished by my wife, in the second batch of stones she tumble polished.
“There is all this untouched beauty, The light, the dark both running through me…”
Changes come, turn my world around
Changes come, turn my world around
I have my father’s hand
I have my mother’s tongue
I look for redemption in everyone
I wanna wear your ring
I have a song to sing
It ain’t over babe
In fact it’s just begun
Changes come, turn my world around
Changes come, bring the whole thing down
I wanna have our baby
Some days I think that maybe
This old world’s too fucked up
For any firstborn son
There is all this untouched beauty
The light, the dark
Both running through me
Is there still redemption for anyone?
Changes come, turn my world around
Changes come, bring the whole thing down…
“Changes Come” by Over the Rhine
One of the Riverton stones from my wife’s first batch of tumble polished stones. It has flashes of blue residing deep within…
Go find a jukebox
And see what a quarter will do
I don’t want to talk
I just want to go back to blue
Feeds me when I’m hungry
And quenches my thirst
Loves me when I’m lonely
And thinks of me first
Blue is the colour of night
When the red sun disappears from the sky
Raven, feathers shiny and black
A touch of blue glistening down her back
We don’t talk about heaven
And we don’t talk about hell
We’ve come to depend on
One another so damn well
So go to confession
Whatever gets you through
You can count your blessings
I’ll just count on blue
Blue is the colour of night
When the red sun disappears from the sky
Raven feathers shiny and black
A touch of blue glistening down her back
Blue
I picked this stone up at Riverton and then rejected it – I thought the “rust” in it was unsightly. My wife saw its promise and tumble polished it in her first ever batch. I think it is worthy of its own tune and name…
“Gabriel’s Oboe” is from the movie “The Mission”.
The scene featuring this tune from the movie, The Mission, with Jeremy Irons as Father Gabriel:
“The Mission” is rated among my top ten movies. It is about the clash between Jesuit missionaries and European slave traders in South America in the 18th century, about friendship and betrayal, the plight of indigenous people, greed and evil and forgiveness and redemption. It is spectacular, sumptuous, enlightening, provocative, disturbing and challenging.
In Te Ara, the online New Zealand Encyclopedia, is a map of beaches in New Zealand where you can find agates and other interesting stones. This is a very selective map and does not include, for example, Riverton at the bottom of the South Island, one of the best places for semi-precious stones.
“Although New Zealand lacks the commonly accepted ‘precious gems’ (diamond, ruby, sapphire, emerald), many local stones deserve our recognition” (from the Introduction to “Gemstones”).
This booklet, originally published in 1985 in the Mobil New Zealand Nature Series, is long out-of-print but now available online as a pdf file. The pdf file is 36 pages long (each of its pages consist of two of the original booklet pages when its comes to numbering – the original booklet numbered each side of each sheet, making 74 pages). It is a great source of information on the range of precious and semi-precious gemstones to be found in New Zealand – from greenstone to agate to jasper to petrified wood, and many more. It contains some great photos of the many different types of stones, supplemented with notes on where these specimens have been found (see below for the entry on “Carnelian”). Reference is often made to places such as Birdlings Flat, Rangitata River, Orepuki, Kakanui, Mt Somers, the Coromandel Peninsula, and Takaka.
Joyce Thornton also wrote the entry on “Gemstones” for Te Ara, the Online NZ Encyclopedia. This entry has some excellent photos of different types of stones, such as “Silicified Wood and Plant Material“. “Chert, Flint and Jasper“, and “Greywacke Pebbles with Quartz Veins“. In 2004, she received the NZ Order of Merit for services to Earth Sciences.
