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.

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Description

✨ Polish your passion, rock your world! 🪨

UNIVERSAL COMPATIBILITY - Works seamlessly with all rock tumblers, optimized for National Geographic models.
PRECISION POLISHING POWER - Four-stage grit system sculpts, smooths, pre-polishes, and shines for museum-quality results.
BULK SUPPLY FOR BIG PROJECTS - Over 3 pounds of premium grit refills enough to polish up to 20 lbs of rocks, gems, or glass.
AWARD WINNING STEM EXCELLENCE - From the Toy of the Year-winning Blue Marble brand, inspiring creativity and scientific curiosity.
EFFORTLESS MEASUREMENT STORAGE - Wide-mouth containers with screw-top lids and a 10 mL scoop ensure no grit goes to waste.

The National Geographic Grit Refill Kit offers a complete four-stage silicon carbide grit system designed to transform rough stones into dazzling polished gems. With over 3 pounds of grit, a precision 10 mL scoop, and universal compatibility, it supports up to 20 lbs of rock tumbling projects. Trusted by STEM enthusiasts and backed by an award-winning brand, this refill kit ensures professional-grade results and inspires hands-on creativity.

Specifications

ASIN	B01MRKI4W0
Battery Types	No batteries required
Brand	Blue Marble
Colour	white
Customer Reviews	4.6 out of 5 stars 13,653 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

15.11.2021

M**E

Passt und erfüllt seinen Zweck

11.01.2026

L**E

Parfait !

Indispensable pour utiliser la polisseuse de mon fils. Il y a de quoi faire pour un moment.

22.01.2025

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

31.12.2025

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