How many oz is in each container?

1 Coarse-16oz. 2 Medium-13oz. 3 Pre-polish-12oz. 4 Polish-11.5 oz.

I just opened this and finished with grit one, went to put grit 2 in and bottle open and 1/2 full. How do I contact seller?

I would go through Amazon to get an answer for your problem.

Can it be used together ?

Each grit is a different fineness intended for a specific purpose. We do not recommend using them at the same time. We do recommend 1 TBS grit per per 1 LB rocks, at each cycle. For further information please contact us at help@natgeotoys.com.

After each step for the rocks in the kit, my rocks dry with a dull white finish. It doesn't show when it is wet. Am I doing something wrong?

No. I find that after tumbling with the finest grit after the last step... and thoroughly allowing the rocks to dry, a nice coat of wax or oil brings out the color beautifully.

National Geographic Grit Refill For Rock Tumbler Works With National

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$175.69

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Sold byAmazon USADelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

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Description

✨ Turn rough stones into polished treasures — your DIY gem journey starts here! ⚒️

UNIVERSAL COMPATIBILITY - Seamlessly works with all rock tumblers, optimized for National Geographic models for flawless results.
PRECISION POLISHING POWER - Four distinct grit stages sculpt, smooth, pre-polish, and shine your stones to museum-quality brilliance.
BULK SUPPLY FOR BIG PROJECTS - Over 3 pounds of premium grit lets you transform up to 20 lbs of rocks, gems, or glass in one go.
AWARD WINNING STEM EXCELLENCE - From the Toy of the Year-winning Blue Marble brand, inspiring creativity and scientific curiosity.
EFFORTLESS MEASUREMENT STORAGE - Includes a 10 mL scoop and secure containers to keep your grit fresh and perfectly portioned every time.

The National Geographic Grit Refill is a premium 4-stage silicon carbide grit kit designed to polish and shape up to 20 lbs of rocks, gems, and glass. Compatible with all rock tumblers and optimized for National Geographic models, it includes over 3 pounds of grit, a precision 10 mL scoop, and secure storage containers. Backed by award-winning STEM educational expertise, this refill kit ensures professional-quality results for hobbyists and collectors alike.

Specifications

ASIN	B01MRKI4W0
Battery Types	No batteries required
Brand	Blue Marble
Colour	white
Customer Reviews	4.6 out of 5 stars 13,728 Reviews
Educational Objective	STEM
Global Trade Identification Number	00816448020636
Included Components	4 Stages of Rock Polishing Grit, 10 mL Grit Scoop, Rock Tumbling Instructions
Is Assembly Required	No
Item Dimensions	14 x 14 x 10.8 Centimeters
Item Type Name	Rock Polishing Grit Media
Item Weight	1.78 Kilograms
Manufacturer	JMW Sales, Inc.
Manufacturer Part Number	NGBULKGRIT
Material	Silicone
Model Number	NGBULKGRIT
Number of Players	1
Operation Mode	Manual
Size	One Size
Sub Brand	National Geographic
Theme	Rock Tumbling
UPC	816448020636
Unit Count	1.00 Count

Reviews

F**M

Helps Poshing

It helps shaping stones too..it is a little sound and I'm living 2floor so I put a box on it to make the noise more silent

15.11.2021

M**E

Passt und erfüllt seinen Zweck

11.01.2026

A**X

Muy satisfecha

El proceso de pulir piedras es algo largo, pero el producto hace su labor. Viene suficiente cantidad para varias tandas y es muy sencillo de usar, ya que cada paso esta numerado.

13.07.2025

V**Z

Good product

As advertised

31.12.2025

C**N

Très bien

C'est un petit investissement, j'aurai aimé pouvoir acheter pot par pot car je n'utilise que le n°1 et n°3, mais ça reste très efficace, bon rapport quantité/qualité/prix. Et une seule cuillère c'est dommage car il reste toujours un peu de poudre quand on la vide donc on contamine un petit peu les autres pots... Mais ce n'est qu'un détail.

20.06.2024

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TrustScore 4.5 | 7,300+ reviews

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