how many pounds of rocks can the grit tumble

The instructions for the Tumbler does not give a specific weight. It recommends not filling the Tumbler barrel more than 1/2 to 2/3 full. If you overfill the Tumbler, the built-in sensor will automatically protect the motor inside by turning the Tumbler off. It further recommends if this happens you should remove some of the rocks.The grit to be used in the Tumbler comes in premeasured packets for the Tumbler size itself. I hope this helps.

Are these uncut gemstones sourced ethically? Can you provide evidence if so?

I only buy from reliable dealers. I buy a lot from National Geographic through Amazon. I’m not sure where I can find proof. I’m sorry I couldn’t give you a better answer.

Where were the rock mined?

I think they were mined in Madagascar.

Does this kit list the Mohs hardness of the different stones? I know you're not supposed to polish rocks with different hardness together

No, there is not a Mohs hardness scale included in this kit, but you should be able to locate a copy online.

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National Geographic Rock Tumbler Refill Kit 3 lbs. of Rough Gemstones and Rocks for Tumbling Including Amethyst and Quartz Supplies Include Tumbler Grit and Jewelry Accessories

Product ID: 82423825

Details

Brand
Blue Marble
Age Range (Description)
Kid
Color
Multicolor
Theme
Geology
Item dimensions L x W x H
5.37 x 5.31 x

💎3 lbs of 9 gemstone varieties

📿4 jewelry accessories included

⚙️4-step grit system for flawless polish

$108.01

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Sold byAmazon USADelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

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Description

💎 Polish your passion, wear your story.

WEAR YOUR ART - Craft custom necklaces, rings, earrings, and keychains with included jewelry fastenings.
STEM MEETS STYLE - Engage in hands-on geology learning with an award-winning kit that blends education and elegance.
EFFORTLESS CREATIVITY - No assembly or batteries needed—just pure, tactile fun for professionals and hobbyists alike.
TRANSFORM ROUGH TO RADIANT - Turn raw stones into museum-quality gems with a 4-stage tumbling grit system.
CURATED GEMSTONE COLLECTION - Explore 9 unique gemstones including Amethyst, Tiger’s Eye, and Rose Quartz for endless creativity.

The National Geographic Rock Tumbler Refill Kit offers 3 pounds of 9 diverse rough gemstones, including Amethyst and Quartz, paired with a comprehensive 4-stage grit system to transform stones into polished gems. Complete with jewelry accessories and an educational guide, this award-winning STEM kit empowers creative professionals and hobbyists to craft personalized jewelry while deepening their geological knowledge.

Specifications

ASIN	B07H7WFWYT
Age Range Description	8 years and up
Best Sellers Rank	#44,507 in Toys & Games ( See Top 100 in Toys & Games ) #19 in Kids' Rock Tumblers
Brand Name	Blue Marble
Color	Multicolor
Customer Reviews	4.7 4.7 out of 5 stars (2,414)
Educational Objective	STEM
Global Trade Identification Number	00816448025914
Included Components	3 Pounds of rough Gemstones
Is Assembly Required	No
Item Dimensions	5.37 x 5.31 x 5.44 inches
Item Type Name	Rock Tumbler Mega Refill Kit - 3lbs Gemstones of 9 Varieties
Item Weight	1.36 Kilograms
Manufacturer	JMW Sales, Inc.
Manufacturer Maximum Age (MONTHS)	1188.0
Manufacturer Minimum Age (MONTHS)	96
Manufacturer Part Number	NGGEMREFILLMEGA
Manufacturer Warranty Description	We're proud to make the highest quality products which are backed by exceptional service.
Material Type	Plastic
Model Number	NGGEMREFILLMEGA
Operation Mode	Manual
Set Name	National Geographic Rock Tumbler Refill Kit
Size	3 Pounds
Sub Brand	National Geographic
Supported Battery Types	No batteries required
Theme	Geology
UPC	816448025914
Unit Count	1.0 Count

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$108.01

Duties & taxes included

In stock

Sold byAmazon USADelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

Buyer Protection · Full refund if your order doesn't arrive as described.

Desertcart purchases this item on your behalf and handles shipping, customs, and support to USA.

Secure transaction

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TrustScore 4.5 | 7,300+ reviews

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