It's a tiny coin, perhaps Celtic, probably Southern Indian.. Who knows? I don't. [solved]

 Hi folks! I hope that some knowledgeable numismatist may be able to identify this coin for me. As a collector of modern coins, I have never dared stray into the realms of the ancients, partly because I love modern World Coins, and partly because I do not need a habit I cannot afford. I found it in a bulk lot of modern coins for which I paid 14.70 NZD. Its cost to me was then, 0.26 NZD. It was in a little sheath of its own which suggested it may be important.

 I have run a photo of both sides through Numista's image search and that came up with nothing much… I had more luck with a Google image search, which leads me to believe it is possibly Celtic in origin. The bottom photo leads me to that. The top photo got more hits for ancient Greece, although they are two sides of the same coin. 

This coin is approx. 6-7mm in diameter, and depending on where you measure it, perhaps 1mm to 3mm thick (ref. the top photo). It certainly looks as if it could be silver.

If anyone can identify this I would be grateful. A valuation and I'd surely be indebted to anyone who can.

 Thank you, Arthur Yapp

I have no knowledge on such coins but Im pretty sure that this is a coin from southern India.

Hope someone will help you ID it.

Hi, look at Travancore Chuckrams.

Sorry, I had notifications turned off. I'll investigate this line of enquiry. Thanks, AY

There is no doubt there are similarities to some of the Travancore Chuckrams, but equally as strong were the Celtic similarities. I don't ‘wish’ it to be anything, just to know the truth. Is it possible that an exact type of coin exists? They all seem so different to one another… Cheers, AY

Celtic slaters are out - they seem to be much larger. The other Travancore coin I own is about the same size (the weight of that one is 0.60g on a jeweller's scale), so I think we may well be heading in the direction of Southern India. Thanks, asimov37 and apuking!

Yes, good ID @asimov37 ,  this is a Travancore silver chuckram, Rama Varma IV, AD 1860-1880, KM#21

https://www.zeno.ru/showphoto.php?photo=104193

Thank-you Seeker55! Is there a Numista number for this one? And what would such a coin be worth, please? Also, do these coins all look a little different to one another?

 I'm grateful for what you have already given me. Thank you, Arthur Yapp

Here's the Numista page

N#82182

These are hand-struck coins, so are going to vary with dies and striking positions on the flan. 

For the most accurate idea of value, I'd search EBay for recently sold examples in similar condition

 Thank you, Seeker55, you have made my day. I'm thrilled to have found such a cool coin in a bulk buy from my regular dealer! 

 It was a bag filled with mostly smaller coins, “That I (he) can't be bothered putting into flips.” Well, I can! This is probably the most interesting coin in a bag full, of about 57 coins, but not the only one well worth having. I was pleased to get a tin RAMA VIII Thai 25 satang, among many other excellent and interesting coins. There is not one that I've tossed to the side.

 I don't think it was simply a case of, “can’t be bothered.” I buy a lot from this person, and he has a generous streak that he tries to hide.

 Love ya, Rich…

 Thanks again, Seeker55! Also, Asimov37, and apuking! 

 With my very best regards, Arthur Yapp