user30725: I am a beginner to Arduino, and a relative beginner to electronics in general. I have the official Arduino Starter Kit. I've looked through my bag of components looking for a black diode but was unable to find it among all of the LEDS & the other black components. 

user3917: While the ArduinoStarterKit page at arduino.cc lists “5 Diodes [1N4007]” as part of it, and has a picture where 5 diodes apparently appear slightly left of center in the top row, several other pictures that come up in a google images search for official Arduino Starter Kit apparently don't show the diodes.  Eg, as at arduino starter kit.  But 4 Best Starter Kits for Arduino Beginners does show them.  
Note, unless you are working with medium to high AC voltages (eg above 50 V) you can substitute 1N4001 - 1N4004 which have lower PIV ratings but also slightly lower forward voltage drop.  For many beginning projects, 1N4148 signal diodes will be adequate and perhaps less expensive.

user28569: 1N4007 are usually black with a white stipe indicating the cathode. Use a magnifying glass and you should be able to see the marking.

user30725: They are stuck next to a string of resistors.


user29234: This is image of 1N4007 diodes. I think now you can find them easily.


30725: <p>I am a beginner to Arduino, and a relative beginner to electronics in general. I have the official Arduino Starter Kit. I've looked through my bag of components looking for a black diode but was unable to find it among all of the LEDS &amp; the other black components. </p>
 3917: <p>While the <a href="https://www.arduino.cc/en/Main/ArduinoStarterKit" rel="nofollow noreferrer">ArduinoStarterKit page</a> at arduino.cc lists “5 Diodes [1N4007]” as part of it, and has a picture where 5 diodes apparently appear slightly left of center in the top row, several other pictures that come up in a <a href="https://www.google.com/search?hl=en&amp;site=imghp&amp;tbm=isch&amp;source=hp&amp;biw=1400&amp;bih=896&amp;q=official+Arduino+Starter+Kit&amp;oq=official+Arduino+Starter+Kit&amp;gs_l=img.3..0j0i24k1l3.1366.1366.0.3233.2.2.0.0.0.0.88.88.1.1.0....0...1ac..64.img..1.1.87.0.eMHm1WmRzhk#imgrc=IBZ9ux6HxlSEfM:" rel="nofollow noreferrer">google images search for <em>official Arduino Starter Kit</em></a> apparently don't show the diodes.  Eg, as at <a href="http://www.arduino.org/products/kits/arduino-starter-kit" rel="nofollow noreferrer">arduino starter kit</a>.  But <a href="http://www.nbcdaily.com/4-best-starter-kits-for-arduino-beginners/3883/" rel="nofollow noreferrer">4 Best Starter Kits for Arduino Beginners</a> does show them.  </p>

<p>Note, unless you are working with medium to high AC voltages (eg above 50 V) you can substitute 1N4001 - 1N4004 which have lower PIV ratings but also slightly lower forward voltage drop.  For many beginning projects, <a href="https://en.wikipedia.org/wiki/1N4148_signal_diode" rel="nofollow noreferrer">1N4148 signal diodes</a> will be adequate and perhaps less expensive.</p>
 28569: <p>1N4007 are usually black with a white stipe indicating the cathode. Use a magnifying glass and you should be able to see the marking.</p>
 30725: <p>They are stuck next to a string of resistors.</p>

<p><a href="https://i.stack.imgur.com/aGuGG.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aGuGG.jpg" alt="Diodes and resistors"></a></p>
 29234: <p>This is image of 1N4007 diodes. I think now you can find them easily.</p>

<p><a href="https://i.stack.imgur.com/ZeK1r.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZeK1r.jpg" alt="enter image description here"></a></p>
