Stamping and Embossing

Stamp Unused

There are several stamps that fit your description.
If your stamp looks like this:
http://www.mysticstamp.com/viewProducts.asp?sku=1213
American collectors would identify it as U.S. Scott catalog number 1213 or 1229.
1213 has perforations on 3 or 4 sides, 1229 is perforated on only two sides.
If it looks like this:
http://www.mysticstamp.com/viewProducts.asp?sku=1283B
It could be 1283, 1283B, 1304, or 1304C. The plain numbers are perforated on 3 or 4 sides. The numbers with letter suffixes are perforated on only 2 sides.

All of them are quite common with a minimal catalog value of 20 cents, but no one is likely to offer you as much as catalog value for yours.
If your stamp is unused, your best value would be to use it for postage.

Another, older possibility is:
http://www.mysticstamp.com/viewProducts.asp?sku=710
which is Scott catalog number 710. It has a catalog value of 20 cents used, and $1.50 mint.

Elephant rubber stamp mounted unused Graphistamp $6.00 Time Remaining: 36m

Stamp MeTender Unused Rubber Mounted Wood Stamp Butterfly $8.00 Time Remaining: 39m

1996 Art Impressions Unused Rubber Mounted Wood Stamp Cow Front Back $9.99 Time Remaining: 45m

NICB 5 mounted rubber stamps Nutcracker Monkey Hand Shy Man Teardrop UNUSED $9.95 Time Remaining: 50m Buy It Now for only: $15.95

1996 Art Impressions Unused Rubber Mounted Wood Stamp Horse Front Back $9.99 Time Remaining: 52m

INKADINKADOO mounted rubber stamp Abstract Plant Leaves UNUSED $9.95 Time Remaining: 57m Buy It Now for only: $15.95

INKADINKADOO 1995 mounted rubber stamp Pink Panther Easter Egg Basket UNUSED $7.95 (1 Bid) Time Remaining: 1h 1m

1996 Art Impressions Unused Rubber Mounted Wood Stamp Little Girl Front Back $9.99 Time Remaining: 1h 2m

SonLight Impressions Unused Rubber Mounted Wood Stamps Ballerina Girl w Candle $8.00 Time Remaining: 1h 19m

INKADINKADOO mounted rubber stamp Tree Handmade in USA UNUSED $3.95 Time Remaining: 1h 23m Buy It Now for only: $5.95

3 SonLight Impressions Unused Rubber Mounted Wood Stamps Angel Shepherds Sheep $8.00 (1 Bid) Time Remaining: 1h 28m

INCA STAMP mounted rubber stamp Mermaid Sea Siren BH15 3AH UK UNUSED $9.95 (1 Bid) Time Remaining: 1h 30m

2 Ant Transfer Unused Rubber Mounted Wood Stamps Kewpie Dolls Mermaids $11.42 (3 Bids) Time Remaining: 1h 35m

THE RUBBER CAFE mounted rubber stamp Large Fancy Goldfish UNUSED $8.95 Time Remaining: 1h 38m Buy It Now for only: $15.95

2 Stampa Barbara Unused Rubber Mounted Wood Stamps Clowns 1987 $9.99 Time Remaining: 1h 40m

STAMPIN UP Set of 4 Friendship Grows 2001 UNUSED $4.99 (1 Bid) Time Remaining: 1h 45m

Lot of 5 Unused Rubber Mounted Wood Stamps Borders Darcies Annette Watkins $9.99 Time Remaining: 1h 50m

Stampin up stamp sets Most are NEW and unused $50.00 Time Remaining: 1h 50m

The Rubber Room 2 Unused Rubber Mounted Wood Stamps Left Right Hand Fingers $8.00 Time Remaining: 1h 58m

STAMPS HAPPEN Dragonfly Happiness UNUSED Large Stamp $6.99 Time Remaining: 1h 59m

MAKE AN IMPRESSION 1994 mounted rubber stamp Round Tulip Stained Glass UNUSED $7.95 Time Remaining: 2h 1m Buy It Now for only: $14.95

Food Stamps Unused Rubber Mounted Wood Stamp Ice Cream Sundae $4.00 Time Remaining: 2h 3m

Food Stamps Unused Rubber Mounted Wood Stamp Wine and Cheese $4.00 Time Remaining: 2h 7m

ART IMPRESSIONS 1996 mounted rubber stamp Catty Old Lady Tea Party UNUSED $9.95 Time Remaining: 2h 9m Buy It Now for only: $15.95

PSX K 1359 UNUSED Mounted Rubber STAMP PANSIES Heart $25.00 Time Remaining: 2h 9m

1990 Stampa Barbara Unused Rubber Mounted Wood Stamp House Sun Trees $6.00 Time Remaining: 2h 12m

AMERICAN ART STAMP 1996 mounted rubber stamp Kliban Cat Gathering Hearts UNUSED $26.00 (7 Bids) Time Remaining: 2h 17m

Stamp n Around Unused Rubber Mounted Wood Stamp Leprechaun $5.00 Time Remaining: 2h 18m

GRAPHIC RUBBER STAMP mounted rubber stamp Ghost 753 1J UNUSED $5.95 Time Remaining: 2h 31m Buy It Now for only: $9.95

THE PAPER GARDEN mounted rubber stamp Three Wise Men Christmas Xmas UNUSED $7.95 Time Remaining: 2h 37m Buy It Now for only: $12.95

Unused Stampin Up Angels Mini Retired $9.99 Time Remaining: 2h 38m

UPTOWN RUBBER STAMPS mounted rubber stamp Snowman Hope Sandi Gore Evans UNUSED $7.95 Time Remaining: 2h 45m Buy It Now for only: $12.95

UPTOWN RUBBER STAMPS mounted rubber stamp Fear Not Sandi Gore Evans UNUSED $5.95 Time Remaining: 2h 51m Buy It Now for only: $10.95

EUREKA STAMPS mounted rubber stamp God Danced the Day Your Were Born UNUSED $5.95 Time Remaining: 2h 55m Buy It Now for only: $10.95

IMPRESSIONS IN INC 1996 mounted rubber stamp Tiger Rug Zebra Stripes UNUSED $8.95 Time Remaining: 3h Buy It Now for only: $14.95

StampinUp Live Like You Mean It New unused with mounting blocks $3.99 Time Remaining: 3h 1m Buy It Now for only: $7.99

STAMP OF EXCELLENCE mounted rubber stamp Eskimo family UNUSED $4.95 Time Remaining: 4h 12m Buy It Now for only: $8.95

CUTE NEW UNUSED POOH WITH CHRISTMAS TREE CHRISTMAS GIFTS RUBBER STAMP $3.99 Time Remaining: 5h 39m Buy It Now for only: $4.50

Unused 1992 Nellie Edge Rubber Stamp I CAN READ LISTEN TO ME Children Rainbow $4.50 Time Remaining: 11h 51m Buy It Now for only: $4.50

4 Sunflower Mounted Rubber Stamps Unused $4.99 (3 Bids) Time Remaining: 13h 43m

NEW Mirror Image Stamp unused 247F 1 stamp $4.00 Time Remaining: 18h 10m

New Unused 1998 Lrg Stampin Up Rubber Mounted JUST MOOVED New Address Phone $6.95 Time Remaining: 18h 42m Buy It Now for only: $6.95

2005 STAMPIN UP ALPHABITS Full Set with Case Unused New Alphabet Letters $9.99 Time Remaining: 21h 13m Buy It Now for only: $9.99

Norwegian Santa on Straw Horse at Mailbox Rubber Stamp New Unused Mounted $3.99 Time Remaining: 21h 22m

Chevrolet Corvette Set of 3 Rubber Stamps 2 unused 1 gently used Mounted $16.01 (4 Bids) Time Remaining: 21h 34m

Primary Source Rubber Mounted Wood Stamp Unused Jill Craig Rose Border $7.00 Time Remaining: 21h 34m Buy It Now for only: $7.00

Rubber Monger Rubber Mounted Wood Stamp Unused DragonFly $7.00 Time Remaining: 21h 38m Buy It Now for only: $7.00

Geisha Girl Cute Mounted Rubber Stamp Co Motion Rubber Stamp Co c1989 unused $3.99 Time Remaining: 21h 43m

2000 DelRose Unused Rubber Mounted Wood Stamp Butterfly $6.00 Time Remaining: 21h 52m Buy It Now for only: $6.00

Mail Expressions Unused Rubber Mounted Wood Stamp Butterfly $9.99 Time Remaining: 21h 54m Buy It Now for only: $9.99

SPECIAL DAY Stampin Up Rubber Stamp Unused $9.99 Time Remaining: 21h 57m

The Write Impression Unused Rubber Mounted Wood Stamp Butterfly Michele Sleight $7.00 Time Remaining: 21h 58m Buy It Now for only: $7.00

Embossing Arts Rubber Mounted Wood Stamp Unused Rabbits Bunnies Easter $7.00 Time Remaining: 22h 21m Buy It Now for only: $7.00

Stamp Oasis Unused Wood Mounted Rubber Stamp Dragonfly Dragonflies $9.99 Time Remaining: 22h 24m Buy It Now for only: $9.99

RUBBER STAMPEDE 1992 mounted stamp Z 173 C Confetti Posh Impressions UNUSED $3.95 Time Remaining: 22h 27m Buy It Now for only: $8.95

EFFIE GLITZFINGER 1994 1996 mounted rubber stamp Sun Moon Star Saturn UNUSED $4.95 Time Remaining: 22h 27m Buy It Now for only: $8.95

ANN TICIPATIONS 1996 mounted rubber stamp Popping Champagne Cork UNUSED $4.95 Time Remaining: 22h 27m Buy It Now for only: $7.95

RUBBER STAMPEDE mounted stamp A 2536 B Tulip Stamp heart flower UNUSED $3.95 Time Remaining: 22h 27m Buy It Now for only: $8.95

STAMPA BARBARA 1995 mounted rubber stamp Scrapbook Photo Frame UNUSED RARE $5.95 Time Remaining: 22h 27m Buy It Now for only: $9.95

STAMPA BARBARA 1987 mounted rubber stamp Scrapbook Photo Frame UNUSED RARE $9.95 Time Remaining: 22h 27m Buy It Now for only: $16.95

RUBBER STAMPEDE mounted stamp Z043E Majestic Mountains Posh Impressions UNUSED $3.95 Time Remaining: 22h 27m Buy It Now for only: $7.95

ANN TICIPATIONS 1996 mounted rubber stamp Mountain Lake UNUSED $4.95 Time Remaining: 22h 27m Buy It Now for only: $7.95

ANN TICIPATIONS 1996 mounted rubber stamp New England Covered Bridge UNUSED $6.95 Time Remaining: 22h 27m Buy It Now for only: $9.95