Not sure ben,
maybe topaz, zircon, garnet or citrine... best way to narrow things would be a hardness test. Try scratching one piece with quartz which is 7 on the mohs scale, if it leaves a lasting mark then its softer than quartz if not its harder.
If it leaves no mark then its about equal hardness so possibly citrine or topaz.
If its scratched easily then it may be amber or agate.
Goodluck,
TGW.