![North of Kuruman on Twitter: "Did you know that bulbs not only help us to identify stones, but they can also tell us about HOW a tool was made? Hard hammer percussion ( North of Kuruman on Twitter: "Did you know that bulbs not only help us to identify stones, but they can also tell us about HOW a tool was made? Hard hammer percussion (](https://pbs.twimg.com/media/E3hk1wYUUAwbiAT.jpg)
North of Kuruman on Twitter: "Did you know that bulbs not only help us to identify stones, but they can also tell us about HOW a tool was made? Hard hammer percussion (
![Amazon.com: Medical Hammer - Percussion Hammer 6" long with hard rubber head. : Industrial & Scientific Amazon.com: Medical Hammer - Percussion Hammer 6" long with hard rubber head. : Industrial & Scientific](https://m.media-amazon.com/images/I/11x3Xk1cUzL._SY445_.jpg)
Amazon.com: Medical Hammer - Percussion Hammer 6" long with hard rubber head. : Industrial & Scientific
![Jastrzębia Góra 4: example of direct percussion with both hard and soft... | Download Scientific Diagram Jastrzębia Góra 4: example of direct percussion with both hard and soft... | Download Scientific Diagram](https://www.researchgate.net/profile/Dominik-Plaza-2/publication/261008679/figure/fig5/AS:392387009499140@1470563761208/Jastrzebia-Gora-4-example-of-direct-percussion-with-both-hard-and-soft-hammer-on-soft.png)
Jastrzębia Góra 4: example of direct percussion with both hard and soft... | Download Scientific Diagram
![Blades produced via hard hammer direct freehand percussion with core... | Download Scientific Diagram Blades produced via hard hammer direct freehand percussion with core... | Download Scientific Diagram](https://www.researchgate.net/profile/Anthony-Boldurian/publication/238448935/figure/fig3/AS:669046991241248@1536524641933/Blades-produced-via-hard-hammer-direct-freehand-percussion-with-core-hand-gripped-firmly.png)